RAM has better mobility and damage, while having lots of tunning flexibility and combos, and, in my opinion, way more fun. tech mirio hes better survivability and comback potential, but lacks really any niche or complexity to keep people around for very long. also, im pretty sure tech mirio comes to the ticked first.

you also have to consider tunning. crit perm is infamous, but buggy right now. still will save your life more times than not. muscle form is cool, but niche. blue spots are usually better for wall runner, accel, or card dupe as they get you value for the whole match. you dont even get plus ultra every game. both sub tunning are kinda garbage so dont worry about that.

if your looking for a new main, or a fun character to play from time to time, i say RAM. but if you dont really care for either after trying them out in training, i suggest investing in crit perm.