Re: Is there something specific to make me choose a new gpu?
No support for three monitors without SLI isn't really a con. You aren't going to be able to play modern games with three monitors unless you use SLI or CF anyway, so the fact that a single Ati card can push three monitors is only a plus while you are sitting at your desktop...for gaming it's pretty much irrelevant. Even further, if you do decide to go CF, Eyefinity issues are common and there is still no 3D if you choose to go that route.
The only pro I see to Ati's multi-monitor support over Nvidia's is that Nvidia can't seem to work out their idle clock issues and that keeps the temps higher with multi-monitor setups than with just one monitor.