You can actually just replace the mods in the supercommando gear and it will be identical stat wise to the dps gear, so all you are really comparing is the different set bonuses.

Bad DPS is bad, if your dps can't keep it in their pants long enough, or refuse to follow any sort of kill order, then your problem is probably not a tanking problem, it is a dps problem. Let them die a couple times from the things they pull off you, and if they complain, tell them to kill things in the proper order and to give you a few seconds to establish threat. If you absolutely cannot find dps that aren't idiots, then I suggest you join a guild that will run stuff with you.

PT AE threat is definately better than Jugg AE threat, though most of the time you don't need to pick up EVERY mob. Most trash packs in flashpoints have 1, maybe 2 strongs/elites, and the rest normal mobs. with proper use of CC on the stronger or more dangerous targets, you will rarely have to hold many on you. I always tell my dps to kill the mobs in order Normals>Strongs>Elites>Champions>Bosses. And try to assign kill orders for the stronger mobs, if possible, so dps doesn't pull a mob you have minimal threat on. Normals die so fast they aren't worth trying to tank for the most part, and are only dangerous when left alone to shoot healers for extended periods. If you see one shooting a healer, and have the rage/heat/whatever to thow a little threat on it so it's not shooting a healer, you can do that, but it's generally not very necessary, as long as the dps is killing things in the proper order it won't be alive long enough to do much damage. Meanwhile, since the dps is busy killing the normals, that gives you as the tank extra time to put threat on all the non-CCed strong+mobs, so when the dps does finally get there, it should be very hard to pull threat off you, even if you are dealing with 2-3 mobs. Ops are a little different, EV trash has a lot of enemies, but they really don't hit for much. It's often easiest to just group everyone up and AE threat to the best of your ability, unless a single dps has them all on them, they should be fine. Karagga's Trash, from what I remember, you just CC what you can, and have everyone focus the rest 1 at a time, and you should have an offtank in Karagga's anyway, so it's even less of an issue. As long as your dps is paying attention to kill order and using CC properly, threat shouldn't be much of an issue. It just takes a bit more coordination than "Everybody run in and start AEing." it's amazing how many supposed "Tank Problems" are actually "DPS Problems."

While I wouldn't throw Tank DPS, and thus Tank threat, out the window, as it is important, I have very little issue with single target threat as a PT, geared pretty extensively towards the mitigation side of things. This is of course given that my dps give me a few seconds to build some threat before they unleash the fury. In flashpoints occasionally a geared dps will pull off me, because nobody really cares about giving the tank a second, and I'm not stressing too much about max threat. In ops, at least up through HM, as I haven't done nightmare yet, I haven't had any real issue with threat, and we aren't running into enrages, as long as dps don't die to fight mechanics. Any issues I might have can generally be solved by a quick taunt and/or early and good use of guard on the most "dangerous" dps. On the flip side, at least so far, damage on me hasn't been a huge issue for our healers. I could see myself dropping a bit of mitigation for additional threat, should threat start to become an issue as my dps become more geared, and not be too adversely affected. All in all, faster boss kills are nice, but it's better to have a slightly slower kill than to have a dead tank, or dead dps because healers are OOM from spamming the tank rather than keeping the dps alive. If the boss dies, the amount of damage it actually did is relatively unimportant, so saving some theoretical amount of healing by downing a boss a few seconds faster isn't worth considering imo.

To be fair, damage meters can actually be quite useful. Especially for things like working out rotations. This goes for raiders and non-raiders alike. For every tunnel-vision dps junkie out there, there is a person using sub-optimal or even flat out bad rotations, simply because they have no idea how much damage they are doing vs what they should be doing. This isn't even counting the other things that meters can potentially show other than just damage numbers, CC breaks, interrupts, healing done, damage taken, deaths, etc. which can all be very useful information.