There can be some effects (positive and negative) of leaving a male intact through to maturity.
IF there are a lot of intact females nearby and any of them go into heat it is possible that an intact male can urine mark inside the house! This is a sprinkle and not a flood for a dog this size, but it is not easy on the carpet or mom (or you).
As we have to separate our male and female during three heat cycles per year (since we've only been breeding once a year thus far) our male generally gets batty when our female is in heat. He has marked inside a few times during these times (and each heat cycle lasts about a month) but he knows he isn't allowed to do that and he has finally stopped doing it. It can take patience and persistence to train a dog not to mark (or go to the bathroom in general) inside the house, particularly if it is territorial behavior. But it is doable.
Of course, there may not be females for miles around, as most people spay their females right away. If there are lots of barking dogs nearby this may also cause some marking behaviors.
My Aussie growing up was an intact male (there are lots of benefits to leaving your male intact) and a male dog moved in next door. This neighbor dog was one of the worst dogs ever! He howled in the middle of the night, barked all day and night, and generally annoyed the heck out of the entire neighborhood. When this occurred my then 5 year old dog Augie did start marking on a wooden tv set we had in the living room. He learned to knock it off, but he did do it several times and clean up was a pain in the neck. He eventually learned to stop, but the neighbor dog "Bart" never did... he was such a butt-head dog! Well, I guess the owners who refused to train him were the butt heads, really!
There are some general pros to leaving the dog intact. Animal rights activists would have us believe that it is unhealthy and can cause cancer if we allow our animals to keep their reproductive organs. I can tell you that is an outright lie. There is nothing healthy about removing a male dog's testicles or removing the uterus and ovaries of a female dog. Both require major surgery and that can also be dangerous. It is important to pick your vet carefully! I have a good family friend who brought their 4 month old beagle puppy to be neutered and he died during the surgery from the anesthesia. It can happen.
There are health benefits for the dog as well. Most "advice" these days is geared toward getting animals snipped long before they even begin doggie puberty. The idea is that most people will not pay attention and watch for signs of sexual maturation and then oops, fluffy is now going to be a parent, and who cares for all the puppies?
Anyway, it is healthy for your male puppy to (at a minimum) go through at least 6-8 months of life with his male parts intact. This is important for him to develop his muscles and his little doggie brain. There are hormones that will be prevented from existing at all as soon as the parts are removed and as soon as they are removed any and all male hormone production will cease. These hormones are what make your male a male, and they keep him healthy and muscular. They also encourage him to be a good watch dog. (not a guard dog, there is a difference. Watch dogs will alert you to danger and intruders, guard dogs will actually attack danger and intruders and may not alert you at all, depending on the breed). Cockapoos make very good watch dogs.
I personally appreciate that my male dog will bark and alert me if there is someone on my property. He doesn't bark at cats, squirrels, or other dogs, but if there is a strange person in the yard he lets me know right away. I like this about him and I wouldn't change that at all. My female does not ever bark unless I command her to. She will occasionally bark with my male dog when she has a litter of puppies in the house. I cannot rely on her to alert me to danger.
In the same way a dog like my male and most intact males will alert you to other major dangers, like a house fire. Often dogs will bark and wake their owners in the event of a fire, smoke, etc. Of course, I prefer to rely on my smoke detectors, but it is nice to know that my dog is there with me too.
I particularly like my male dog sleeping in my daughters' room. This way I would know immediately if there anything was amiss! He'd bark and I'd wake up and that gives me peace of mind. He is better than a security system.
Neutering is very likely to deter this behavior, especially if it is done too early in the dog's life. It is done later (the later the better) this protective behavior can stick around.
Intact male cockapoos are not aggressive, as cockapoos are not an aggressive breed at all. Anyone with an aggressive cockapoo either has a very sick and in pain dog, a very abused dog, or a dog from extremely bad lines (bad bad breeding). The cockapoo breed in general is very sweet and docile.
My male dog allows my 8 month old son to climb all over him. He really likes kids and he will immediately shove his face into any carseat or activity center my son is in, especially if the baby starts to cry. He is there in a second, like he understands that the baby is crying and needs consolation!
The funny thing is that it works. My son now adores my male dog (my female pretty much stays away from the baby in general but she tolerates him without any problems when she must). My male dog will endure major hair pulling, poking and prodding just to be near the baby! We generally have to protect him from the baby and not the other way around.
Anyway, proof positive that unaltered males are not aggressive. Rusty would never bite.
Dogs that are "fixed" have a tendency to become very doughy, soft or outright fat. There are generally zero weight problems associated with an intact dog (male or female).
There are obvious benefits to spaying a female (no cycle to worry about) but there are truly very few benefits to "fixing" a male dog, unless there is a real risk of the dog finding a female in heat.
I have never met an owner of an intact male dog that had their dog run away to search for a female in heat. This is something that is often claimed, but it is pretty much an outright lie. There are certain breeds that are prone to "running away", like hound dogs, (beagles especially) but this is because they are following an interesting scent trail and not looking for a female. Other times it is because the dog is a very solitary, independant breed that feels no real attachment to it's human family (like the husky breed. Beautiful dog, pain in the rear to train and not really cuddly at all)
Cockapoos are extremely people oriented. They will follow you all around the house, constantly. If I go to the bathroom and don't allow them to follow me in they will sit patiently outside the door and wait for me!! :-) They are my buddies. When my husband comes home they take turns following one or the other of us, whoever seems like they might be going somewhere interesting I suppose!
We have no fence in our yard and do not need one as our dogs stay with us much of the time, and if they wander around it is within sight of one of the people family. They like to be with family as much as possible, for this reason they make horrible "outside only" dogs. They would be miserable if they were banned from the house.
I can't think of anything else at the moment. Shoot with any questions you might have!