Most of the diffusers in the market are doing their job rather well. the major differences are mainly in the operational aspect of the diffusers. i.e. the Sto-fen type are usually the most robust and most compact to haul around, since there are not moving parts. but you get less bouncing surfaces (limited by the size of the diffuser). they are usually easy to install / remove at a moment's notice. the demb diffuser type offers a bigger bounce surface area, is relatively easy to carry around (since if folds flat) but it does have flexing joints, so could be rather more fragile compared to others. they also tend to be a bit more tedious to install / remove. the whale-tail / Garry Fong (or more affectionately known as the Maggi Cup) type diffusers are bigger and offers big diffused areas, but they are bulky to carry around. and they look weird on the flash.... hahaha.....

bad news? the A7xx gonna delay to February 2011  and it may be a DSLT ...

thanks for the advise 
this 500 shot thingy is very subjective?

500 shots obtained from bursting with 10fps?

500 shots, in which the exposure for each shot is about 60 seconds?

or is just a normal shot? 

unless u r eating candlelight dinner, iso 400-iso3200 can still do the work, with a slow shutter.

I dun care what sensor this sensor that ... but what I care is will they continue putting OVF on their APS-C model like the A7xx sucessor?

Using 70-300 Kit same like your lens lor