Russ,
Reccomended jetting for starters will probaly be a #45 pilot, and #130 main. You don't say what brand piston, but my preference is a JE.
If you are using the 77mm piston and just trail riding, you will probably be just fine with the stock sleeve. I like the 78mm kit, and alway's use a oversize sleeve/liner. I have had problems ovaling the bore otherwise.
The only reliability issue, directly pertaining to this mod I can think of, is the oem rod. With a little time and some aggressive flogging, not to mention increased compression, seems to take it's toll on the small end. The answer is a Hot-Rod, or other aftermarket. I like the Carrillo, but know it's overkill for the average guy.
As far as what to expect... All else being stock, IMHO it simply makes it an even better woods bike, especially for the larger/faster riders.
A little off topic..I'm waiting for my 80mm nikasiled aluminum sleeved cylinder, to come back from Advance Sleeve as we speak.