Suppose so for cleaning yeh. I wouldnt bother with the core only block though.
I cant see people wanting to remove the cooler for cleaning much before 2 years anyway, at which point if the warranty expires it doesnt make a difference anyway.
I'd just say if you dont plan on watercooling, get whichever is cheapest out of KFA2, Gigabyte Windforce and ASUS DCII.
If you are definitely watercooling, get the EVGA FTW
If there's a possibility of watercoolingin the future, dont get the KFA2, get the Windforce as you can fit a 680 block to it - but the cooler will be quiet enough and well performing enough anyway so it isnt gunna be too loud for use.