Thanks indeed, redguy, as any progress is better than no progress at all. 
Timing of v8 (haven't had the time to install and try v9 yet) seems to be way off though.
Just try Vortex (any region) and see how the logo explosion is totally out of sync with audio, as opposed to a real cart (whether it be NTSC or PAL), that is, unless in GSU "fast mode". So IMHO, your "fast mode" is really normal GSU speed, and your "normal mode" is simply useless 
Hi Ramsis! I may remember you from your Powerpak stuff.
Fast mode actually is faster than real hardware though, as demonstrated in Yoshi's Island, Star Fox, and Doom (with most of us seeming to prefer how Doom runs in fast mode compared to the real cart). I don't know if Vortex has some kind of speed throttle that makes fast mode look right, while regular speed is too slow, but lots of things are currently complicated.
The credits on Star Fox run about 15 seconds too slow in normal mode. However, the speed of stages 1 and 2 are almost right, as demonstrated by some videos I put up earlier in this thread. Meanwhile, I saw another video showing Yoshi's Island runs a little too fast under certain circumstances (original cart experiences some slowdown, while SD2SNES does not).
I think it's fair to say that the GSU firmware is in most (but not all) respects better than SNES9X and Canoe, but it's only been out for what? 6 weeks? ikari_01 has updated Cx4 timing at least four times since 2012 by my count, even though it was already pretty good in 2012.