Although I haven't tried it (other than installing the latest 9128 driver just to see if it fixes my "black screen" crashes issue - it didn't; my next step is to outright disable it, along with everything else I don't use at the moment), I have some potentially bad news:
http://forums.tweaktown.com/gigabyte/42075-my-p55a-ud4p-hdisk-transfer-rate-become-slow-after-firmware-update.htmlApparently he installed the firmware and updated drivers and his 9128 performance decreased to even worse levels. He isn't running SSDs, but regular hard drives (the firmware update and latest drivers are supposed to improve SSD performance I believe).
So - even if the new code improves SSD performance (unproven at this point), it definitely does not look like it turns the 9128 into a top performing SATA 6G controller...
Here is another web page I stumbled upon where a guy who "sounds like" he might be fairly familiar with Gigabyte's implementation of the 9128 controller discusses it and the issues with it a bit:
http://www.overclock.net/11468940-post5.htmlUltimately he says the one and only situation it "might" be worth considering using the 9128 controller (other than where you are totally out of SATA ports and are forced to use it) is where you have a single C300 SSD, you only have one of them (no RAID 0) and you are willing to give up small file read/write performance for a small improvement in large file throughput. I've always thought if I was to go the SSD route I would pick up a pair of smaller SSDs and set them up in a high speed RAID 0 so the 9128 would be once again totally useless to me (unless Gigabyte manages to magically fix the horrific performance of the 9128 in RAID 0).