FWIW, I have an MSR XGK that I've used backpacking both in the USA and Africa. On the plus side, it will burn just about anything. I, personally, have used white gas, paraffin, and diesel fuel. Of course, if you put low-grade fuel in it (read: diesel) you'll get a very sooty flame that will blacken your pots... and anything they happen to come in contact with. DAMHKIT. I'd say that all of the MSR stoves are a bit fiddly, but if you practice at home 3-4 times you shouldn't have any trouble. For some reason, I remember the XGK being decidedly easier to prime and light than the WhisperLite it replaced.
There are 2 or 3 problems with the XGK. The first problem is that it's pretty darn expensive for a stove. The second problem is that the stove is loud. Really loud. I'm not kidding when I say it roars like a jet engine! And the final problem is that like all single-valve MSR stoves it only has two settings: hot and off. There's just not a whole lot of adjustability in between. I never found the latter to be much of a problem, but if you're planning to do gourmet cooking you might want to look at the MSR Dragonfly or something with some more adjustability.