ScryptGuild's coin switching is unique, in that ScryptGuild is on every coin at all times. On the miner end, switching coins is no different from a new block on the network, with the exception of the old work *might* still be valid. It means that we can switch coins without invalidating old work. If your miner submits a share for a previous job after we switched coins, it can still be valid and still solve a block, as long as a new block hasn't been found on that coin yet (in which case it IS stale).
https://bitcointalk.org/index.php?topic=457016.0;all
My understanding is that this pool is run by the admin(s) of BTCGuild, and use custom software they've dev'd over the three years they've run BTCGuild. I've been mining with one rig with them for just under 24 hours. In that time I was able to nab just around 0.01btc/mhs. The front end is nicely done, with lots of numbers. Auto convert to BTC is supported, LTC is planned. You can turn off autoconvert and stick to individual coin pay outs. Estimated hash rate on the front end is very accurate and rejects over the last 24hr is 0.5%.
So far I'm digging it. Couple more days with my one rig and I might swap from clever to scryptguild.
Anyone else using?