Two points I'd make in that regard:
1. I suspect it's the sort of situation where for those who spend seriously a lot of time doing FPS gaming,
they get very used to getting the absolute most out of their control systems, doing highly competitive online
multiplayer; Call of Duty, Halo, all that sort of thing. As they get better, they'll benefit more & more from
better quality gaming mice, keyboards, mbds with ultra low latency net links, etc. A bit like the way one
can get used to the quality of any display (I did, VR being my research field for a long time), such gamers
very likely notice the impact of lesser frame rates and lag as they improve, and thus wish to have higher
frame rates, faster response times, etc. TN panels certainly provide this, but it's always at the expense
of colour accuracy and viewing angles. However, for players at the top, the faster response times probably
are worth having, for that extra edge. It's a minority though. Btw, I sometimes wonder where the modern
peculiar FPS visual style of having rather garish unrealistic colours for explosions & urban environments is
a cheaty way of making up for the fact that TN panels have inferior colour reproduction (just a thought).
2. There's no point having high-frequency 'gaming' monitors (by that I mean anything significantly above 60Hz)
unless one's GPU setup is able to provide a minimum frame rate that's at least the monitor refresh for most of
the time. Depends on the game of course, but really we're talking top-end GPU setups, good CPU/mbd combo,
and so on. Thus, again it's a minority who can afford to put together such systems, presumably the same
people who have the time to spend on the relevant games, and the money to go with it (hmm, think 20s to
40s males without partners & thus salaries to burn. 😀)
Hence, I would say that the people who want these sort of setups for gaming very likely can tell the
difference, because of what and how they play. And if they're playing at 1440p or higher then the differences
are likely even more noticeable. For the average gamer though, at 1080p, probably not. Thus, a 60Hz display
with a GPU setup that can support 60Hz nicely would IMO be the sweet spot for most users. I'm just glad
IPS models have come down in price so much since I bought my HP, eg. the Dell is more than 50% cheaper.
Note that I prefer 1200-height displays because I find that extra height makes such a difference in so many
situations, especially for general desktop use, eg. web browsing, but games look better too. It's a pity that
the market erred towards 1080 as it meant pricing for 1200 displays stalled for a while, but if the OP can get
that Dell for a good price then go for it I say, s/he'll be plenty happy.
Ian.