SLS Cancun is probably one of the more refined hotel/resorts in Cancun. It is nestled at the end of the hotel zone strip in Puerto Cancun, which (in my opinion) is much nicer than the trash that the Hotel Zone has become. The clientele and vibes are very upscale chic luxury, the views amazing, rooms big, food good and excellent vibes/service. It is also close to the Puerto Cancun shopping mall which is very large. It has a lovely beach club (albeit a bit quiet - though it is low season).
Cancun itself is rather unremarkable (Tulum much more super-luxe jet set vibes that I am inclined towards) and trashy, but the SLS and Puerto Cancun is a diamond in the rough. If you do want to just grasp Cancún for a day before going to the much better Tulum, suggest spending 2 nights in Cancun max and if you do so, stay at SLS (you won’t regret it).