I've got a water-cooled 7990... I flashed the bios so there's no power limit now (it's limited to about 500watts stock) but I haven't bothered over clocking it (2 cores, each getting 700hash)
I'll post up my middlecoin graph when I get home and have the link
stay way from the ASIC mining stuff.... they only mine bitcoins, and the bitcoin difficulty is so high it'll take forever to get your money back (ir ever)
bitcoins are sha256, which ACSI/FPGA/whatever can mine really fast
litecoins/didgecoins etc.. are scrypt (a different kind of cryptography) especially made to be hard to mine with anything other than a GFX card
(they use a bit of gfx card ram, where bitcons use next to none)
asci for scrypt coins are starting to come out... but they're crap right now... it'll be a while before they're profitable, and as soon as they are they'll be sucked up by bitcoin millionaires running in data centres who will kill the profitability of scrypt coins...
then some other type of coin will come out, so you can mine that with a gfx card (and on and on)
I keep getting tempted by setting up a gfx mining rig with 5 cards in it... and priced it up a few times... it could do well... or something could change after a week and it would be worthless... it's too hard to say
(check this for profitability of mining bitcoins directly
http://www.bitcoinx.com/profit/)
if you stick with middlecoin (of one of the other pools like it) they mine whichever coin is most profitable at the time, sell it for bitcoins and then send you the bitcoins... it's risky to hold onto no-name coins, there's loads of them and there prices are very volatile