i dont know about lumia tablet .. personally im interested in moving to 1520 later on (big screen great for browsing but not so big as an ipad) ..
i got iPad already so i need a middle ground between my Lumia 920 (Screen size 4.5") and iPad-4 (Screen size 9.7").. Lumia 1520 feels perfect (screen size 6") .. personally i prefer either Apple's iOS or MS's WP8 OS , not Android OS (dunno why i hate android OS usability, its personal preference though)