I have been curious as to others feel the game is being played currently. I don't want to know, specifically, how it should be played, but how it IS being played.
Right now I just see tons of people running into each other in a disorganized matter, and then getting killed by bad decisions either relating to rushing in with a long range mech against short range brawlers, or trying to run a short range brawler through a solid minute of LRM fire.
I have seen threads where people have this massive discussion related to imbalance in mechs that I do not see as being imbalanced in the game, IE when confronting them I always see them get defeated in detail by myself or my friends I play with, and we simply don't have any idea of how threads such as "Aeros are OP!" or "Madcat configuration XXXX is the best ever."
The reason I say this is because as I have played the only mechs that seem to have any value to bring on the field are ones that are dedicated to a single role, and have some overriding advantage in that single role. None of the mixed advantage mechs are worth taking at all, and all money can be spent at every level for a single role advantage mech.
For example.
Role: Initial mech - Uller A for any map except Inferno, where I use an Osiris B (the ac20 one).
Role: Intermediary mech - Warhammer B - The GECM allows you to get close on any map except for Frostbite. I haven't found a good intermediate mech for Frostbite yet, maybe the Shadowcat with Gaus? I still use the warhammer B on this map but it is much less effective.
Role: End Stage all around best mech - Novacat A - This mech has everything. It is anti mech, anti BA, and Anti Air (as long as not being directly targeted).
Even the removal of the er large it had this mech is still the best. If you can begin engaging an enemy at long range, you have the option of disarming the enemy mech, or simply coring it, with risks for either. If you disarm the mech, you will take damage from whatever remaining weapons it has when it gets to you, if you try to Core it and don't succeed it might have enough weapons to kill you.
Role: Best Surprise! your screwed mech: Mauler/Madcat MK2/Atlas C (whatever the heavy autocannon configs are). I have been completely defeated in detail when surprised by these mechs, you simply cannot live for a long enough time if they get in 300 meters of you. I have been killed from a full mech to completely dead before I even realized what was happening against these mechs.
Role: Long Range Support: LRM boats (Puma, Cougar, Vulture, Catapult)
I only see these mechs being effective on Frostbite and to some extent on Marshes.
------------------------
Map play.
Marshes: One team is close to buildings and cover, and the other team is less close to buildings and cover. I cant remember which.
IF your on the team where you have tons of open space and can force the enemy, going with novacats and LRM mechs is the way to go.
If your on the other team and have cover, and want to draw the enemy in, then novacats are the best. All of this is thrown to disarray if someone brings a Long Tom.
FrostBite: I have seen this map played from both sides now (I usually play clan because I hate freebirth scum). The Clan side has a massive advantage on this map in position and availability of cover. Playing as clan you can move up with a novacat into the covered buildings area, and have a good shot on many enemy positions there, the enemy cant poptart behind hills effectively, and the enemy has to cover a LOT of ground before it can get into cover, all the while being visible from LRMS by the clan.
As IS I recommend players fall far back from where I see people sit currently, either using the main hill outside of the base as cover, or going to the "left" relative to their base to use the more mountainish area as cover. Do not engage in the open area at all except for the longest range LRM mechs.
The Novacat is devestating for the clan on this map, but can be completely shut down and forced into a support role (IE keeping the backfield clean) for the LRM mechs. I played that role last night, every time a bigger enemy mech decided to come kill our LRM emplacement mechs, I simply disarmed them and then finished them off. Quite sad really.
Inferno: This is the only map where one side or the other doesn't matter as long you focus on capturing the hill, I cant remember what sector but if you have played you know what hill I am talking about. Once you gain that hill you can force your own terms of battle, and you can force short range brawls that make the Osiris B a good starting vehicle for this map. Because of the terrain the hill is defended from both sides from missiles, so you can use true brawling mechs and have enough cover to get to the hill without worrying about LRMS.
SandBlasted:
Long Range mechs all of the way, Novacat is king on this map, LRM boats are king, you have to pick your ground. As a Novacat you can either go directly into the valley (one end or the other) and have good cover and the ability to pick apart mechs in a funnel. As a warhammer you can force short range engagements in the valley. As LRM mechs and or Novacat you can also flank one of the pyramids and force the enemy to engage you on your grounds.
This is one of the few maps where I would say that dedicated anti Air is a good thing to have, there is just not enough leeway with all of the open ground for the ground forces. This is where an autocannon HUIT is worth bringing.
Mirage:
This is my favorite map, you guessed it, warhammer B or Novacat. Each side has the ability to force engagement at medium to close range, LRMS are relatively worthless depending on how you force the play and on individual skill of your teammates.
For me I go clan and just as you exit the main value on the right of the base there is a mountain and some rough terrain, I just hang out there and kill people. Even if the enemy flanks to the left to get more open space, you can still huddle in the mountain area and hold off attack from that.
Extremity: I dont play this map.
-----
Anyway I think I have them all

Also, my general "Team" tactic is to play the game sort of like a flock of birds, the initial attack goes in, takes damage, then slowly falls back through his teammates line to get repaired. Rinse and repeat. This works so well because mechs take so much damage now that you can usually escape as long as you choose when properly.