3 years ago, I nearly bought one from a pal who owns a dealership. I passed, because the price was just going to add up to turn it into a usable ST. Yamaha did have to replace the ABS brain (or whatever) - this was subject to some kind of recall. If there are problems with the system, and you have a good dealer, you can push Yamaha to step up to the plate, which will save you $1,800.
The bike is very fast, and very smooth. You will notice some difference between slow speed handling and anything above... 40mph or so, compared to a conventional front-end. It's really cool, however, and nothing very different from a normal bike. You can't beat the wow factor of a bike with a front end built like aircraft landing gear. It feels very stable, and it gets attention. It's a shame Yamaha didn't stay with the design.
My other friend/classmate, with the Yamaha dealership, said maintaining one wasn't bad, atall. He sold two or three of the things, new, but they didn't jump off the showroom floor. He loved the bikes when they came out, and was likewise disappointed they were so short lived. I still wish I'd taken his advice, and went ahead and got the thing from my other bud.