An actual discussion in a LRM thread? That is almost unheard of, what a pleasant surprise! Sorry if my previous comments were a bit snarky, it was nothing personal, it ist just being pro-LRM in this forum is a Don Quijote kind of deal... it gets annoying after a while.
So, on topic: Like I already mentioned before, after the LRM5 nerf with the latest patch, there are esentially no Mediums and Heavies left that can be used as LRM boats. So comparison is difficult even on a theoretical level, and I personally play almost only Heavies and Assaults.
Stat-wise, my Awesome-8R has each other mech I own beat in all categories, and my Highlander IIC - B and Supernova - A are in my "over all" Top 5, with one Marauder IIC and a lonely Shadowhawk-2H keeping them company. I am not an extreme Pokemech collector, but I still own a lot of mechs and I don't play that often at the moment, so apart from the mechs I used for FW I only have a handful of mechs with enough games on them to be usuable for statistical comparison. I am currently in the process of rectifiying that situation

Will take 2-3 days to do, so far (~30 games done), no noticeable differences.
Also, while we are at it, I though I do an overview of LRM mechs in the game, and why non-bad players dare to use use LRM Assaults. Kind of "back to topic", instead of slinging insults.
Mediums - IS:
Kintaro - Golden Boy: The "boy wonder" of LRM5 spamming, made almost unusable by the LRM5 nerf. The only Medium LRM mech I own, and it is really bad now. The "CT seeking" feature of LRM5s is not there anymore, it is really hard now to even get a killing blow. Increased facetime does not help in a mech with bad hitboxes running an IS XL.
Hunchback-4SP/Trebuchet-7M: Hunchback even with quirks is only 2.6 times worth of LRM10 launchers, not really feeling it. And only 10 DHS, can't really use its backup weapons. Trebuchet with 2.6 times worth of LRM15 has either not enough ammo or gets really slow. Might try it out when the "rule of three" is gone, but not optimistic.
Mediums - Clan:
Hunchback IIC - B / Huntsman: Very similar, can go either ALRM40 and almost no backup weapons, or ALRM30 with slightly better backup weapons and less ammo consumption. I bought one Huntsman a while back, going to refit him as a LRM carrier and see how it goes. But with Clan LRMs being worse than IS LRMs, and no quirks, I am not really seeing it, going 40 tubes against teams composed of 50-66% Heavies and Assaults. Will report back on this.
Heavies - IS:
Archer: LRM5 spam build is useless now, lousy 2x ALRM20 with bad quirks on a 70t mech... no.
Catapult: same
Heavies - Clan:
Mad Dog: LRM5 spam build gutted, better options for builds with larger launchers
Night Gyr - D / Orion IIC - A: Again really similar loadout options, ALRM60 as core build... now we are talking. The problem is, that build can be done on an Assault without compromising number of DHS, backup weapons or amount of ammo. See below. Could do ALRM40 without drawbacks, but only 40 tubes without quirks, and Clan LRMs at that... no. 60 tubes or bust.
So far nothing really outstanding. Which leaves us where we started: at Assaults
Assaults - IS:
Awesome - 8R: THE ONE LRM MECH (to rule them all, bind them in darkness, etc.)
ALRM60 in perfection. Poetry incarnate on the battlefield. 60 tubes IS LRM coupled with insane quirks and a head mounted TAG conquer ALL drawbacks this build otherwise has, and makes it come out on top as the best LRM mech in the game.
Cyclops / Battlemaster - 1S / Mauler MX-90 etc.: they work, but if you already decided to use an IS Assault as a LRM boat, there is no reason not to use the Awesome. Even less so with the "rule of three" going away soon.
Assaults - Clan:
Highlander IIC - B / Supernova - A: They can run the ALRM60 build way better than Clan Heavies can, 2x LPL as "backup" weapons, enough heatsinks, enough ammo, all the trimmings (no TAG on the Highlander, but higher E mounts for the LPLs). Honourable mention for the ARLM80 build on the Supernova, which cuts down the backup weapons to a laughable 3x ER-SL. I originally thought it might be more of a troll build, but it is almost as effective as the other build.
Conclusion: with the possible exception of the Night Gyr / Orion IIC, Assault mechs are currently the only mechs worth using LRMs on in the first place. Shocking, I know. I might have forgotten some hidden gem, but I doubt it.