I, like the OP, am looking to move to a 3 (maybe 4) monitor setup on my Linux system. Like him, this is primarly a system for software development. And like him, I was unaware until this thread of the multi-monitor support in Kepler. So I've already learned something important. I've been looking at Radeon 7870 cards, and it would appear that the comparable nVidia would be a 660.

Are the multi-monitor support with Eyefinity 2.0 (as on the 7870) indeed comparable, or are the reasons why I would choose one or the other? One advantage to nVidia is that Radeon cards (with the exception of the few Sapphire Flex models) require an active DisplayPort to DVI adapter if one wants to connect 3 non-DisplayPort devices, but nVidia does not have this limitation. On the other hand, and this is fuzzier, Eyefinity has been around longer and is presumably more mature. On nVidia, I believe a single X screen (as implemented in the card/driver) is limited to 3 monitors; the 4th must be a separate X screen. It's not clear to me if Eyefinity has a similar restriction.

Of possible importanance is that the monitors will be heterogeneous. Currently the system has two 24" 1920x1080 monitors. I expect to add a 27" 2560x1440,

To add a bit of history, Ted Stevens got to the Senate by red-baiting Senator Ernest Gruening over the Vietnam war. Gruening had been one of only two senators, as I recall, who voted against the Gulf of Tonkin resolution. Ignorance and facile oversimplification have always served him well.