Well, they're here now and I was right they ARE the 112 shader part in spite of being on the G80. My 3dmark went from 6502 to 10982 with no overclocks or tweaks applied and performance in FSX w/ acceleration is roughly double with the same quality settings.
I realize that I won't see 50% increases clear across the board but so far I'm VERY happy with this purchase! The only real downside was setting up SLI and putting up with a couple of blue screens until I got the drivers configured under Vista. (First time I've ever BSOD'd Vista

)
I can highly recommend this upgrade and with Newegg letting these evga cards go for 229 a pop with a 30 bone rebate (on one card only) for me it was one of the better Hardware purchases I've made in a while.
Thanks Vodka and Mermaid for your insights and I think I'll be off to enjoy FSX and Bioshock for a while!