To once again be clear, our group's complaint with pinning had nothing to do with realism or lack thereof or whether it's psychological or physical. Our issues were purely gameplay issues. In its most basic form, the issue was as follows. It is easier to score one 5+ on two dice than it is to score one 4+ on one die. But it's harder to score one 6+ on two dice than it is one 5+ on one die. I think that point is made in either the Advanced Rules or the Scenario Pack, when advice is given on when to autofire. In short, if you need a 4+, the advice is to autofire, and if you need a 5+, the advice is to not autofire.
In a Legions of Steel, an AK Rifle and a Deadbolt Launcher are quite similar weapons, with the AK Rifle given a slight edge due to the flexibility of a higher rate of fire. In normal circumstances, a Deadbolt Launcher requires a 4+ on one die, or a 5+ on two die, to score a kill. In those same circumstances, an AK Rifle requires a 5+ on two die, or a 6+ on four die, to score a kill. The net result for both weapons is that the 5+ on two die is the preferred attack. Where the AK starts to gain an advantage is in specialized circumstances, where spreadfire maikes the ROF 4 6+ kill more attractive, or where standing still makes a 5+ on four die an option, and so forth. Where the Deadbolt Launcher gains an advantage is at medium range or covering -1, where a single 5+ is better than the two 6+ of the AK Rifle. And so forth. Bottom line: you can make an argument that the weapons are equally powerful, though they demand slightly different tactics.
Now look at Planetstorm. In order to score a kill in normal circumstances, the AK Rifle now requires a 6+ on two dice, while the Deadbolt Launcher requires a 5+ on one die. this is where the "equality" of the weapons starts to break down. the Deadbolt Launcher gains a clear advantage. Additionally, the -1 GM of the T70 armor is no longer balanced with the +1 Move score for a typical Fantasian. Again, this is due to the skewing effects pinning has on kill numbers. However, if you look at the UPV of a AK Rifleman versus a G1 Nightmare, the AK Rifleman costs 3 points more. Yes, Gauss Grenades are better than nachtmachers, but that only counteracts the armor disadvantage (the +3 modifier helping counteract the -1 armor modifier), not the weapon one, and that's only two charges while the units are closing on each other. And yes, the AK Rifleman has a MASLAW, but he'll have to be extremely lucky to get close enough to use it. Bottom line: in most circumstances in Planetstorm the G1 will have an advantage over the AK Rifleman, specifically due to the pinning rule, and yet the AK Rifleman costs more.
You can look at the other high rate of fire weapons and come to the exact same conclusion. Two Flechette Gunners...6 ROF at 5+...versus an AutoRAM gunner and e-loader...3 ROF at 4+...and yet the flechette gunners cost a few points more. Basically any weapon that requires a 5+ kill is a weapon to be avoided.