In comparison to the last gen low end imacs, its a dope upgrade, but it comparison to the mid/high end imacs, not much of an upgrade at all. For example, in my perspective (i have 2.93 4gb with geforce gt120) not much of an upgrade, unless you want a 27 in screen (24 is big enough) and the graphics card is like barely better (like similar difference to 2.93 processor to 3.06 processor). Being able to upgrade to 16gb is pointless really, 8gb is too much, 4gb is plenty.
I mean, LED is dope, kinda want that, but 16x9 is kind of just a gimmick. The new mouse is cool too, along with wireless being standard now. Overall, dope upgrade to the low end, little to no upgrade to the mid/upper side. For consumor computers, the upgrade is ok. For people who don't want to break the bank on a mac pro and arent worried about upgrading, its pretty sick.