I don't find LRM boats as effective in this game as in games like MW3 or MW4. However, I do like using LRMs as a support weapon for more balanced platforms. For instance:
AS7-D-DC: 1xLRM15/20, 1x SRM6, 1xSRM4 2xMPLAS 1x AC10 ECM/BAP/Artemis
In this role, I use the LRMs for indirect fire support while closing with its horrible 47.5 kph stock movement speed, then try to stay 200-300m from targets to stay in the ranges of all four weapon types. The LRMs are very effective; I'd say 1/4 to 1/2 of my overall damage in many matches comes from LRMs. Being able to run BAP/Artemis alongside the SRMs and LRMs is very helpful in that, and the Atlas doesn't have to worry as much about taking damage from being in direct line of sight due to its armor and ECM.
STK-5S: 6xMPLAS 2xLRM10 2xLRM5 2xAMS BAP/Artemis
This mech is quite a bit more LRM boat-y and is similar to a Catapult C1. However, higher armor capacity and the MPLAS help to discourage lights/mediums that assume you're a LRM boat and rush you. Heat is a bit of a problem with the MPLAS however. The playstyle very similar to what someone else described in this thread with their Cats, softening up targets with LRMs during the initial skirmish/brawl, then closing to 200-300m to use the MPLAS in the midgame.
I've tried running LRMboat Stalkers, Catapults, Trebuchets, and Awesomes, but just don't find them as effective as a more well-rounded 'Mech. Catapults and Trebuchets are the only canon LRMboats in the mechs we currently have, after all.
EDIT: I think AMS is one of the things that makes LRMs as weak as they are. Almost every heavy/assault and most mediums I see that can run AMS are doing so. When you have 2 or 3 AMS together, very few missiles will get through. I know that LRM5s are chainfired because it decreases total spread, but I'm not sure why it is as popular because that just gives more time in AMS range per missile. I hardly have to worry about incoming LRM fire with my STK-5S, as it has dual AMS and I'm usually in AMS range of another 'Mech with AMS. If anything, the fact that so many people run AMS shows that they are scared of LRMs
Edited by ShishiX, 20 July 2013 - 08:16 PM.