Many reviews say this expansion board is amazing. Roland advertises that it has all the sounds of the sr-jv80 synth expansion boards and other boards as well.
I have the sr-jv80 synth expansion board and all the sounds of this board and the others Roland says comprise this board are NOT there.
There are lots of patches for sure. Usability of the patches for most musicians, well it's not there.
So, one is paying lots of money for a limited number of good sounds. In comparison with the sounds and patches on the sr-jv80 expansion boards, well it's just not there. Sure, the enhanced sampling is great. But sr-jv80 boards are vastly superior and I will continue to use (and treasure) my xp-30 keyboard that utilizes the sr-jv80 patches.
If you are an MC-909 owner/user making electronic dance music or anything within that realm...consider the SRX-05 a major power-up! Installation is a breeze and takes about 2 minutes. It will take you HOURS to get through all the new sounds you'll have on board...trust me, I agonized for days over which board to add on to the 1-expansion slot of my 909 before finally pulling the trigger. Overall I'm extremely satisfied with my choice and discover new sounds and inspiration every time I fire up my groovebox.