I play the Pathfinder adventure card game on my iPad quite a bit (played it IRL with my gaming group as well.) The app will show you your percentage chance for success, but in my experience, anything less than 90% means I'm going to miss xp My real life experience has largely mirrored this.
Anyway, I will admit that melee weapons are not an optimal, or even particularly effective, use of tonnage...but I still like them. In fact, one of the things that really bugs me are mechs with 'claws' in the art that don't actually mount claws! I mean, claws were a thing when the Kodiak II and the Cave Lion came out, but do them actually mount them? Nope. Just the 'battle fists' quirk. Grrrr! I probably kick more than anything else, but once you get up to around 60 tons with TSM, I become a bigger fan of punching. Being able to knock a mech's head clean off, even if it isn't super likely, it just good, wholesome fun! TSM kicks can be hideous as well. If your mech is big enough, you can force the PSR for being kicked AND a PSR for doing 20+ damage in a turn, all in one hit.
Oh, and the TSM Berserker? Oh...oh my sweet baby, how I love thee! People talk about the AC/20 on the Hunchback being an area denial weapon. A TSM Berserker turns that up to 11. Even the bot in MegaMek knows to stay the hell away from one of these.