There is no such thing as the "perfect" machine.
They all have their own particular issues.
I owned a Yamaha Viking for 2.5 years. It was a great machine. EXCEPT;
*Every week or so, someone else on the forum blew up a tranny because of one particular bolt that backs out. Yamaha will not fix it.
*blown head gaskets were common
*Exhaust pipes breaking off at the head
*rear shocks sagging within the first year of ownership
Add to that the fact that it has crappy suspension (far less travel than the Honda), is underpowered, and is NOISY. One of the things I love about the Honda is how quiet it is.
Kawasaki Tyrex;
*you think the Honda seat gets warm? It's nothing compared to the Kawi, or the CanAm, for that matter. The Pioneer will walk all over the Tyrex in the power area. Honda also has better suspension, and a more comfy cabin.
Polaris;
Where do I start....
Every machine except the Honda run belts. Some are better than others (Yamaha) but they still get shredded from time to time. That'd be a nice job to do on the trail don't ya think? Not.
The bottom line is Honda makes a dam good machine, it's not perfect, but it can be made to be darned near. If you've had the udates, your clutch should be golden. The clanky shifting will smooth out over time as it gets broken in. Water ingestion is fixed quite simpy by using the kit from a member here. Not a big deal. The doors rattle a little bit.. RG3 makes new hinge inserts that should help that a lot. The bed rattle on a lot of machines can be simply adjusted out. On mine I had to put a short piece of fuel line on the bed side of the latch.. works like a charm.
I also am a long time Honda ATV and motorcycle owner. My 2002 Rancher has somewhere just south of 10,000 miles on it. I replaced the shift drum at about 5K, the angle sensor at 7K, and am on my 3rd bar-mount E-brake holder. Pretty damn good service for sure.
I'll bet that if I take care of my Pioneer the same way I have the Rancher (after I do the little stuff that Honda forgot to do) it'll last just as long.
Relax. IMO, your kids picked the right machine. Trust me, I did my research before I switched from the Yamaha.
You own the best game in town.