Well I've used the Tyros on seven jobs now, and, at the urging of several SZ members, need to give my impressions.
I've really been too busy to get into the thing very deeply. Mostly I just set up one bank of registrations and started playing.
It is quite similar in operation to the PSR2000/2100, but different in some important areas.

Things I really appreciate:
The dedicated intro and ending buttons!!!
The mic volume adjustment knob on the front panel.
The aux inputs (I run the laptop through them).
The nice, big screen.
The overall feel of quality in the buttons and keys (compared to 2Ks)
The improvement in the sounds and styles, using the mega voices and new voices. I particularly like the new guitars such as Blues Guitar, Stratosphere, Dyna (I'm calling on memory).
The Vocal Harmony presets work as they should. The first to do that since the PSR9000. Both the 2000 and 2100 had mistakes, minor though they were.
I like the little tray on the right-hand side. I suppose it's to hold floppies, but I use it to place my wireless mouse for the laptop.
I like the large amount of User memory. Not sure how much there is, but so far I've put everything I need there, and haven't put anything on the hard drive yet. The hard drive was fairly simple to install, btw.
The vocal processing and effects seem to be improved. I've had several people comment on the way the vocals sound.

I'm sure there are more features I like a lot that I'm forgetting right now.

Things I don't particularly like:
I don't like the locations of the Fill button. I liked it better next to the intros because I often use it during a song and play an intro as an extra fill variation immediately after or before. It won't be difficult to adjust to it.
The pop-up screen is very nice, but created a problem with the keyboard stand setup I was using, so I'm having to work out a new setup. Also, when using the removeable Yamaha speakers, I have to make some stand adjustments.
There are two button pushs necessary to go between preset styles and User styles. Only one on the 2K.
The sax voices are still the same. I think it's time Yamaha worked on the Tenor sound.
As you can see, there isn't a lot to dislike so far.

As I use the Tyros more and get deeper into it (next I plan to work with the overall compressor/limiter--the defaults didn't work for me), I will post more.

Overall I like the Tyros much more than I even thought I would. It is well-suited for what I do. I would really hate to go back to 2000 or 2100.

DonM