AFAIK, all telcos are on 4G LTE cat3 (75Mbps) at the moment except for maxis which have been doing limited trials on LTE advanced (cat6 300Mbps) on a few sites in KL (since june 2015). Sunway pyramid is probably one of the few (as I honestly dont know).

Personally I wouldn't be going crazy for the fastest LTE at the moment as the goal post(s) keeps changing every 6-12 months. Rolling out just one base tower station is never cheap.

Bottomline, fastest LTE at the moment doesn't mean much if one is limited to 1GB fair usage quota monthly .....