Bit hard to say mate, you get the sense that the ground is a fair distance away but I can't say I'd be able to fly close to pattern height or something just by judging the ground which I was pretty close to doing IRL.
On the other hand stuff like tanking is so much easier, on a screen in 1920x1080 it took me 3\4\5 attempts to get a probe contact and even more to hold it, but using dk2 it was usually first or second attempt making contact and holding purely due to the fact it's easier to judge distance and speed, there was definitely a noticeable feeling of 'closeness' to the tanker compared to the scenery in that respect too.
Ordered my cv1 yesterday too as I can't wait any longer