i think lack of website updates.. in the interim you should check with support team on what would be greatest firmware for your deployment keeping in mind not just controller hardware, but also AP etc..
9.8 MR3 is considered to be most stable, and 9.12 MR1 patch 1 is bleeding edge with new features and enhancements, therefore Ruckus will always recommend that you use what is considered to be the most stable release so you get the best experience
Note: All fixes that are in 9.12 MR1 patch 1 are also in 9.8.MR3.
As AlphaDog states, definitely check AP support. We have to stick with 188.8.131.52.14 because it is the last firmware that supports the ZF7962 AP. However, it is missing some fixes that are said to be in the later versions.