Actually we are only complaining because the payouts are below expected. If they were fine, nobody would bother with technical details.

Either way, I have the impression that any of these pools are a waste of time. Maybe these pools should have a rig with at least a single 7950 pre-mining the so called "most profitable coin" for 2 minutes before making the switch, to make sure that stalls and rejects don't eat up hash rate.

Blindingly switching according to calculations similar to what seen on coinchoose, doesn't cut it. My rig is stable, cgminer reports the same 870 Kh/s, yet HashCows mining KrugerCoin, the pool reports 160 ~ 200 for the full round. Where is the remaining hash rate going? Rejects, stalls, lag and God knows what more ...

I suspect I'll stick with my setup of switching to the most profitable WITHIN a subset of "good" pools/coins, now that I had the hassle to set this crap up.