I don't notice any grid lines on my SP3 but I notice them all the time on my Nexus 4 phone.
I have a tiny bit of light bleed on my SP3 on the top right corner but I only notice it on black screen and to be honest I would expect it to be fairly common on this sort of device, may be wrong there but I'm not going to nitpick over that as it's a tiny flaw on what for me has been a very positive experience with my i7.
I actually noticed the same with light bleed last night.