I personally do this–about the same as Ato with 2X70 in spikes with long break, and this comes at the end of a long warmup (and of course John Smith is somewhat notorious for long warmups).
But for someone running ~11.0/22.8, how long of a break (and how extensive of a warmup) would you use?
Another point–a single hard effort FROM BLOCKS. I find that much of the time advantage following a hard effort is simply getting prepped for the block start. So I bring practice blocks when I can, and I see higher level athletes bringing everything from blocks, to sleds, to towing apparatus (no comment here in favor of using them!) to meets as part of warmup. And in those cases where you are only allowed minimal access to the track for warmup, put 1/2" spikes in and accel from your blocks on grass, like Franno.
Thoughts?