I find SMGs aren't as effective as they were in COD4 due to various factors. Does anyone else feel this way too? I'll write down some of the reasons I feel is the cause of this below.
There aren't that many useful perks in the third slot, so most people just use Steady Aim or Ninja. Ninja's only really needed in S&D matches, so Steady Aim is easily the most common perk in its category for pretty much every other game type.
What this does is allow AR users to have good hip-fire accuracy, coupled with a powerful AR that has good range, fire rate, recoil and stopping power, it can kill enemies up close easily unless you're using a single or burst fire weapon like the FAL/M16. These are just a few factors that weaken the SMG class' advantage in CQC.
The maps are also generally larger now, with more open areas. Close range combat isn't as common because maps usually have a few small 'buildings' and everything else is outdoor combat. At such range, ARs have an advantage over SMGs in terms of accuracy and damage delivered.
Now lets look at what is currently regarded as the best SMG among many competitive players; the UMP45. It has good power, being able to kill an enemy with only 3 bullets at point blanc based on my tests. It doesn't have the greatest fire rate, various ARs have a better rate of fire than it in fact. The UMP45 is surprisingly good at ranged combat, just fire in bursts and it can be kept under control easily.
Still, an AR with Stopping Power most likely requires less hits to kill someone at long range compared to an SMG. If the same rules apply from COD4, then SMGs are weakened at long range, the bullets do less damage, so we can assume the UMP45 takes 4-5 shots to kill someone without stopping power, compared to an AR which would probably take 2-3 hits for a kill.
The only advantage the SMG keeps over other classes is its mobility. But now that we have the Lightweight perk, is that really a big advantage? It is an advantage still, but not a noticeable one. Snipers have the same mobility, just give them a sniper rifle and a machine pistol, then you have a class that's just as deadly in my eyes. So yeah, anyone disagree with these observations?