By asking a CPU Miner (or any miner that isn't at least some X% of the network's total power) to process the entire getwork solution space before performing another GetWork, you are dooming that Miner to a very significant percentage of Stale shares.
Yup, you're right. CPU miners are doomed either way. Either they ask for new work so fast that they don't even have a chance at getting through 1% of a single getwork request, or they risk working too long on a getwork and the network's block count increases by one making their work stale. CPU miner's are simply too slow to be able to run at a high efficiency against any pool, or even the bitcoin network at this point. Because the average block is solved in less time than it takes on a average CPU to process even 1 getwork all the way through, it's really not worth using a CPU to mine for bitcoins at this point.
When taking GPU's vs CPU's, it's truly a night and day difference. You could take the most powerful DUAL CPU/QUAD CORE Intel server (~12,700 khash/s) and run it against a ATI 5750 card (~150,000 khash/s) and the ATI card will smoke that server hands down...we've tried.
We built and tested this the Pool with GPU's.
Could you imagine us trying to build and test a pool with CPU's?! ROFL
So you admit that your pool too favors faster miners when you specifically (incorrectly in every way except your one shortsighted emotions over statistics way) chided Slush's pool for doing so in your OP.
Quote from: FairUser
[...] or weight based shares" (slush's pool) which favors faster cards [...]
And only getting ~12,700khash/s is ridiculously low for a high end Intel CPU. People are reporting upwards of ~24,000khash/s when mining with their CPUs.