I voted 'Very good' as I believe in leaving room for better titles..
However I am very pleased with the game. I'm a bit of a stategy fan, not obsessive or particularly good, it's just a genre I've enjoyed over many years and platforms.
I'd also thought it impossible to get the level of usability that they have with such a game on a console. I usually found the PC (or even the Ipaq

) based strategy games to be far better, so much of it because of the controls. I usually treated console strategy games as gap fillers, that I would buy and play to simply feed my craving, whilst waiting for the next decent PC version.. But I've found it difficult to stop playing this Game.
I 'm not sure I'd say it was the best Strategy game ever, (in some ways it might be) but IMO it's certainly the best strategy game I've played on the Xbox360, or any console. It does eat up your life so be warned.. a quick play can turn into 2-3 hours before you know it and some games can be a lot longer..
They have simplified the Micro management of cities and the population, so some hard core Civ fans will no doubt find it a little simplistic, but IMO this has in noway adversely affected the playability. The game probably plays so well and is so addictive as it is quick to pick up and doesn't require the level of micro management that some games do. And although Turn based, it never seems slow or static, of course it's not got the frenetic pace of Dawn of War for example but I enjoy the variation and the pressure can still mount and you can still be 'rushing' to defend or attack.
I almost resent it being so good as I've been missing out on some great COD4 LIVE matches, but I'll be back to that, for now I simply can't put Civ Revolutions Down.