No, I have had many experiences with the 580/597 triples, and never had an issue with them.
I only know to 2 guys that I ride with that have 680 Ultras, and they loved them (one a 96 RMK, the other a 97 SP). One of them was constantly working on his (RMK), though he did mod it a bit. The other guy rode his (Ultra SP) for a year and sold it because of all the small things that went wrong with it (including some chaincase issues). The RMK Ultra eventually blew up the chaincase, which in turn destroyed the engine (not sure how that happened myself), so my cousin stuck my old Indy lite 340 engine in it (lol) and rode it for a season.
These guys also ride pretty hard (our trails are defined a bit different than the lower 48 does) including hill climbing, tree riding and jumping (not that insane crap though). So for cruising and the occasional opening of it up, they probably do better.
My 700 blew up 3 times and was still on the trail more weekends than the 2 Ultras that I have experience with.
most of the issues that popped up were do to differences in design compared to the rest of the polaris line-up. So I go back to my statement, read the book and do what it says, it will last longer. Use the lubes, torques, retightening schedules specified ect. There is no doubt in my mind that these are good engines and such, it is just people don't realise they are different! (look in the manual, you will see)
The 580's were bullet proof, put just under 10,000 miles on 2 1993 models before they were sold. Both are still running good with no rebuilds!