Like CF or not (and I'm fine with it) the SD thing is done and dusted
I still think if you've a decent enough buffer to start with you'll be just fine. I have class 10 SD cards and they're ok for what I do.
I don't think you can make up a small buffer even with very fast cards I tried a UHS-I card in the D7k ok got a few more frames in but with a 10 shot ish buffer you won't get much more. If you had a 20 shot odd buffer across the range of SLT models very few folks would be complaining.
Work the buffer that's my view. Maybe the A99's buffer is "ok" for people time will tell. I don't often hit the buffer anyway the Km5d has 5/6 shots in raw and sure for action you will even jpeg, K-x was around the same buffer hit that a few times. Anything 9-10 and up raw for me is generally safe enough. That 20 frame A57 buffer goes pretty quick if you're shooting raw and at the silly fast fps.
I'm surprised some of these cameras don't have massive buffers you would think they'd shove a 30/40 shot raw buffer in the full frame models and just forget about it