JofaMang :
I understand what the OP is gettings at. I have seen more than once a 4850 upgrader being told a 5770 wouldn't be enough of an upgrade to justify the cost. For some people this may be true, just not for the OP. Glad to hear it when anyone enjoys new hardware. Warm Fuzzies All Around.
Exactly the reason I was so hesitant in getting a card. Many of the people here asking if a 5770 was worth upgrading from the 4850 were met with a resounding "No". However I have quickly found that is not the case. My 4850 could hardly run the opening sequence of Crysis Warhead on enthusiast 1080p, meanwhile my 5770 Just ate through the whole first level; Doing some burn in testing and maximizing my driver capability before I get down to the nitty gritty testing, but for those of us doing minor real world upgrades to our computers, the 5770 is a steal. If you have anything below a Radeon 4890 I would see no reason NOT to upgrade to a 5770. Luckily while I was doing my cpu upgrades I got a CFX Mobo this time, and in about another week or two I am buying another one of these babies and doing my first ever crossfire setup. (I have heard that 2x5770 are as powerful as a $600 5870, over $300 in savings that's nice).
If you are on the fence about getting rid of your old 9800 GTX or 4XXX series that isn't a 4890 (even then if you want some power savings and just a little less performance), don't be. The 5770 is a wonderful card. And right now they are even shipping with free DX11 games (Dirt, Battleforge) so you can get a taste of things to come.