Glad to see you back Danny.
I had an X1, but it was after they had been out for a year or so. No problems that I can recall.
Since then I have had SD1, two Midjays, SD5 and now Audya, with no problem with any of them, except a couple were damaged in shipping.
I've only had one problem with a Yamaha failing and that was with the PSR S900, which Yamaha promptly replaced. I've had most all the models up through Tyros 2.
I have heard the T3 a lot and it is a beautiful sounding instrument. ONe of my gripes with Yamaha is that they are WAY behind on the vocal harmonizer. It is just bad in comparison to Ketron, Roland and Korg and to just about any outboard unit.
As I've always said, the Ketrons, and to a slightly lesser extent Rolands, sound more like a live band, and the Yammies more polished, like a CD.
My experiences with Korg have not been good. I did enjoy the PA80, but the 800 I had sounded awful. They later issued a complete software upgrade that made it much better, but mine was long gone. My other problems with Korg was finding enough variation of styles and the limited fill-ins.
It comes down to whatever you prefer to hear, and to the features you need or want.
I must add that Roland has made excellent-sounding boards with lots of features. They undoubtedly play midi files best of all, if you are into that. I hope they come up with something new sooner or later.
DonM