So first off, the machine I'm really interested in is the new upcoming Xforce Sport Utility machine, however I have reservations.

First, just how reliable is CFMoto, historically China has produced complete crap products but they do it super cheap so people buy it anyhow. With SXS's the CFMoto is for sure less expensive but they are not giving these things away, but I don't want the typical Chinese garbage.
Additionally, I'm not really a fan of buying Chinese products as I feel that it is in a large way supporting a regime that is hell bent on destroying the US and on top of that I hate the attrocities they commit against their own people. Granted, lately with the Trump administration we're looking really bad these days as well and I can't stand that either.......

So how about it, what is the quality of these machines really like?

Helo there, HighMTNRipper
Politics and regimes aside as this can get complex and emotive and start detracting from your key question.
I am sure you do not need me remind you that in life you get what you pay for it is, therefore, difficult to match the quality of a good old USA/Canadian manufactured product. But even Can-Am's are made in Mexico and Austria today. Although the majority of Polaris are made in USA some stuff is still manufactured in Mexico.
So, it will be difficult to match the quality of the above but, as you know you pay for the quality irrespective of who makes it and where it is made. These machines like CFMOTO have their weak and strong points and all machines require care, attention and good servicing to make them last.
OK so let's concentrate on CFMOTO: - Yep once more you get what you pay for, but you do get a lot more for your money on a top spec CFMOTO ATV or UTV. For the same price you get a lot less with the premium brands as you know.
Do they last longer? Difficult to be precise here, if you hammer the nuts off it and ignore regular servicing it will fail and fall apart. If you take care of it do not overload and over REV it, service it on a regular basis with bespoke CFMOTO spares and not equivalent parts from Amazon it will serve you well.
Will it be reliable and not let me down: - A bit like how long a piece of string is, more like expect it to break down and or let you down on occasion. Then again, I have been fortunate enough to have been on the planet for in excess of 69 years, most of that has been spent repairing trucks, semis trucks, Cars, ATV's. In other words, because machines require servicing, maintenance and repair they have kept a roof over my head and food in the mouths of my family. CFMOTO products have not changed that cycle they still provide me with an income.
Are there any known peculiarities issues etc: - Read the CFMOTO forum regarding the model you want there are plenty of trends without repeating them here. This of course is to be expected; you will find similar trends on Can-Am and Polaris forum websites.
The CVT transmission components are Canadian by the way, as usual and Chinese are no exception, on this occasion they did not copy the CVT Canadian design they are supplied from Canada.
The Chinese are very clever people, CFMOTO was established in 1989 and has been manufacturing ATV/UTV's since 2002, I purchased one of the first ATVs to reach the UK. Quality has improved every year along with product and product support.
 On sperate note the Chinese have decimated the Automotive world in Europe and consequential new car sales. They have flooded the European markets with good quality lower priced EV's. "Watch out Elon"

GMSAHFR