Although seen as impractical, unhelpful, or generally stupid, I think they can play an essential role in winning a match.
You've all seen it, the 11 ppc direwolf. This is an ambusher and the ultimate punisher for peeking. Only two salvos before it explodes. An alternative is 15 er large lasers, but that's just cheese. An eye for a eye, literally.
Personally I think glass cannon builds lie in brawler builds. A berserker like the Atlas is entirely different, because in this case the alpha damage needs to be unusually high for its weight, so much so that you are forced to remove armor in places that you'd rather not.
I take a Centurion AH(L) with this build:
CN9-AH
Lack of ammo forces the player to use it sparingly. This build works astonishingly well supporting assault units as it boasts equivalent firepower with a decent speed. This 'mech, on most occasions, can be used to simply take the enemy by surprise and down up to 4 'mechs before falling apart. This doesn't mean you will. Often you will take down only two, but make them count. Hit the assaults early on to crit them so they are rendered easy targets, or destroy them then and there. You don't always need to attack the assaults and heavies. If you find yourself unable to help with that due to range issues or bad positions, attacking lights and mediums can help as well. Lights often go down in a single alpha to the side, and mediums two alphas to the center. I have killed two shadowcats
by myself.
The high amount of frontal armor is an obvious choice. There is no such thing as running away in this 'mech. The majority of matches you will not be alive at the end. If you find yourself flanked, do as much damage as you can. Several crit/dead 'mechs versus one dead you can be game changer.
Although you are charging the enemy, just make sure to torso twist and spread damage in your reload time, and quickly repeat until enemy is dead. Get the maximum out of your armor.
Lastly and arguably the most fun way to play this 'mech is ambushing. It can be difficult because you are not THAT fast, and you don't have ECM. Rounding corners and waiting until the enemy decides to push can take out a few 'mechs that would otherwise destroy the part of your team near you. And as a treat, you can send 58.7 damage straight into their rear armor. Depending on a players preference regarding rear armor, you can sometimes find one well placed alpha can kill and 85 tonner from behind.
Again, there is
NO running away. Take every good opportunity to do damage until the end.