Benchmarks of 256GB SSD vs 128GB SSD

I've been following a few threads about all the pros/cons/opinions of the 128 vs 256 in a new 2011 13" Air, but haven't seen any actual benchmarks of the two against each other. The best I've seen is a few posts with people saying the 256 "should be faster". Does anyone have any actual benchmarks to show if that is indeed the case and, if so, how MUCH faster? I don't really need the extra 128GB of storage, but if it's a significant jump in performance I'd consider it.

Just for the record, I'm not intending this to be one of those "I heard X is better" posts, nor am I misinformed about the fact that just because one has a higher storage capacity that it should necessarily be faster. Since they could be two different drives I'm just interested in whether the 256 is more than a space upgrade.

 

With all due respect, I'd still like to make a decision based on some numbers.