Christian_1,
I have the SRX-03 studio board. The expansion slot is a nice feature. I wish they would have included 2 or four expansion slots instead of one. It sounds like the new SRG01 board is the one to get. It will have a collection of sounds from all of the other SRX boards as well as some new styles.

The key action on the Tyros2 is better than the original Tyros and is fine. It is not as good as the Roland G-70. The key action on the G-70 is better than any keyboard I have ever played. When I play solo piano on the G-70, the dynamics respond like a real piano. Most synth weighted keys do not respond that well.