"Variety" and "fun" are two reasons why I enjoy using SMGs and LMGs.

SMGs fit in the game just fine.  They compliment a particular play style and when used properly to their strengths, out perform ARs.  If you grab an SMG and try to use it like an AR, then ARs will beat you (unless you're some godly player). 

I have no argument for LMGs in this game.  Only thing I can say in their defense is I have seen people use them effectively.

And the Type 95 is not a one burst kill at ANY range, it's actually 2 bursts at range.

These weapon types do accomplish their intended roles, the problem is that these roles aren't very flexible, and not always relevant to scenario the map puts you in. An assault rifle on the other hand is always flexible and relevant.

And even at these more specialized roles, most of the time an assault rifle can do the same thing just as easily. The small advantages that niche weapons get in very particular situations just isn't enough to really make them practical.

For example, LMGs get a handling boost when they're prone. That's lovely if you have a good position to work from, but then again, most assault rifles can produce the same results while still on their feet. Add in stalker, and an assault rifle can stay just as controllable as an LMG even while very mobile. It just isn't worth it to use anything else. Not to a pragmatist at least.

Okay first things first, every stock smg beats assault rifles in terms of damage per second and low time to kill out to around 65 ft. except the ump.  All rapid fire smgs soundly beat all assault rifles within 65 ft.  With the size of the maps keeping engagements within 65 ft. is not very tricky.  Lmgs are worthless.

       I don't understand what you mean about self respect when using a shotgun.  Shotguns (beside the striker) are the hardest weapons to use in mw3.  The type 95 requires 5 bullets past 100 ft.to kill not 2.  And lastly the g36 has the highest damage to fire rate ratio.  Check facts before posting please.

The point of a SMG. For CQC because of weight and size.
The point of a LMG. Longer range supressing fire.

In the game the point is variotion.

Fun? Like the rest of the game.

UMP w/ Range & Extended Mags & MP7 w/ Range & Extended Mags.

They are the only combos to use. Rapid Fire is dreadful and is righfully banned in competitive games.

LMG's are just a waste of time. Dreadful, simple as.

LOLwut? Smg's are far from useless I can use any of them and do as well as a AR can at short range and even nearly as good as some of the AR's at the medium range. Hell I can use Lmg's and beat most AR's at the medium range and long range game, so they are not useless either. It sounds like you have issues aiming for more then a few moments thinking that people should die within 2 seconds or less of you pressing the trigger.

The Lmg's put out more than enough damage if used correctly. They are not meant as run-n-gun guns. They are long and medium range point defense guns. If you are trying to rush or run wiht a lmg and getting owned that is your fault for using them wrong.

funny I feel the complete opposite...AR's are pointless in this game unless you're a camper and even then a sniper with FMG's is much more effective if you are decent with a sniper rifle.

once you learn the maps and can navigate from cover to cover without exposing yourself to longish sightlines, an SMG is MUCH more effective. there is a catch tho, you MUST use rapid fire and I would highly rec using silencer + rapid fire. the p90, pp90m1, mp7 and ump45 are all fantastic choices. p90 is my personal favorite because of the clip size, but mp7 is probably the best overall since it has almost no recoil and the best range of the SMG's.

pp90m1 already fires so fast without rapid fire. with rapid fire it's like a little shotgun with stopping power.

AR's detract from mobility which is BAD in this game where most of the maps are so small.

SMGs are beast in this game, with the right attachments and proficiencies, of course. 

1. PP90 Rapid Fire/EXT. Mags=RAMPAGE

2.MP7 silencer =Quick murders

3.P90 and UMP45.  forgot attachments cus i got them to gold level a while ago.

All these guns are gold for me with a 1.56 k/d with only about 3 1/2 days played.  Only other gold guns i have are the Scar, ACR, and G36C all asault rifles, and the AS50 sniper.

To each their own I guess, i love SMGs for MW3.  I'm a rusher who likes getting multi kill sprays.

PP90M1 and P90 are really good. But you can't use them as an assault rifle. They're SMGs and you should use them like SMGs.

The MP7 is different though. You can literally full-auto from the opposite side of the map on the largest map in the game and hit the enemy with every bullet. I don't know what's easier to use, the MP7 or the ACR.

SMGs are good in MW3. They definitely give you an advantage in close quarters as they should.