So did it work? Yes and No I suppose.
The idea behind Thunderforged was that you could still get some better gear from long-defeated bosses in the raid.
In that case it worked. Before patch 5.4, the first boss was killed so many times, that no one wanted anything of that boss anymore, so it was a sort of 'waste of time' to kill that boss, but you had to. With TF-gear, there is still a chance to get some better gear.
So yes, the TF-stuff is working as intended, good job Blizzard.
....well, yes, the idea was good, but it did mess up some stuff did it not?
All guilds I raided in, and I suppose a large percentage of the raiding guilds, uses DKP (or some form of that) to distribute gear. The more you raid, the more DKP you get, the more gear you can 'buy'. But, up until 5.4, the Ilvl of gear in a raid-dungeon was always the same, with maybe the end-boss having a little higher Ilvl-gear. That is no longer the case.
An other thing is, that it seems a lot more loot drops these days from bosses. In ToT every boss drops 6 pieces of gear. I don't seem to remember how much TBC-bosses dropped, or Dragon Soul for that matter. But 6 seems a bit much. The effect of this much gear is that a lot of people expect to get best in slot items all over, and are actually not going for 'lesser' pieces.
I, for that matter, would not go for a mastery-item. It's my weakest stat, and I know other and better gear will be coming.
Now combine the increased drops with the possibility for TF-gear, and what do you get?
Raiders bidding a lot less on non-TF gear.
Now add some non-BiS gear to the mix, and now we have a genuine problem. Raiders not bidding on items because it is not BiS, although it may be an upgrade to their current stuff.
And that is a problem methinks.
It is a whole cascade going on. If less people bid on stuff, it goes away for less, so more dkp gets hoarded, which is only used on BiS-TF gear.
Oh, and then we have this free-loot system handed to us, by rolling a die. The reason why I didn't had to bid on any weapon since Ji-Kun, because I got a free TF-staff....
Now this all comes from some frustration. Innovation uses a blind-bidding dkp-system with a bleed bid. The amount of times I had to 'pay' the bleed (20% of your bid) is amazing. A piece of gear would drop, and I knew it would be an upgrade for several people, and then it seems no one actually bid, or just bid low. Raiders are 'afraid' to use their dkp, for fear of not having enough when a TF-item drops.
And worst part of this is, that it actually seems to work. Yes, seems, I have no time or actually the will, to actually delve into every raider and see how they have geared, and what they have bid. But it seems that if you only bid the minimum bid on non-TF gear, and in that way only use your DKP really for TF stuff, you will be better geared.
It used to be that you used minbid or lower bids on non-BiS-stuff, but now all non-TF gear is non-BiS.
So, in that case, Thunderforged did not really worked. It made all non-TF gear (except for Tier stuff) weak, and not wanted. So how do you solve that?
Maybe the easiest way would be to put Thunderforged on a different dkp-system, but that means you have twice the administration, which officers really like :p
Maybe the free loot from coin-rolls should no longer get you a free item, but an item to upgrade you weapon to TF, instead of bosses actually dropping TF-stuff.
But, in my humble opinion, One raid-dungeon should not drop different I-llv stuff all over the place.