Tube Dampers - what's the story?

I've read conflicting reports on their effectiveness.Any input or recommendations ??
In a word they work. I have Top Hats on my driver tubes (Brimar EC88) and the difference was astounding. Now, I use the word astounding the case of an AudioPhile, I hear it and I can't go back, the average joe may not hear anything. At about $70.00 for a pair you can't miss. If your tubes are the slightest bit ringy, you should try a set. I think they also absorb some of the Rf coming out of and attempting to enter the tube. Mike
Mikeam is correct in my opinion, also try 3M (yes, the Scotch Tape people) their tube dampers are great, also Tube Socks. All of these dampers improve the sound to a different degree, depends on the tube, the damper and the equipment. Like everything else in this crazy hobby, you must listen to decide which one of these solutions is right for you.
Tube dampers are a subjective thing. I used to think they really made a positive difference and then pulled them off and listened-everything bloomed and became dynamic. I think each piece of equipment needs to be reviewed with and without dampers:it is not a concrete fix, also depends on the microphonics of the tubes you install. Years ago manufacturers never had dampers and everything sounded great-I think a slight ringing my enhance the sound of some equipment. Those 3M dampers are lousy in my opinion, they stick to the tube and deform when removed and can't be reused. If the equipment came with dampers-always use them.
There was a stereophile blurb a few months back about the new Audio Research tube damper's making a very noticeable improvement. The concept being that since tubes are microphonic, stabilizing them will quiet them. It makes sense. I know that one of the differences between the AR vt100mk1 and mk2 is the addition of these. I think they cost $6 each from AR.
I recently installed the ARC tube rings (dampers) in both my SP-8 and the input drivers on the amp, ARC D-115 Mk2. The improvement in focus and separation of the instruments along with a dramatic improvement in dynamics is not subtle. Highly recommended. You can order direct from Audio Research (ask for Leonard)Phone 763-577-9700. They cost 5.00 per tube and there are 2 rings per tube.
The Audio Research dampers you guys like are the 3M. They do not melt on the tube. The tube dampers Otiscat speaks of, must have been another brand, probably made of sorbothane. The sorbothane not only melts and deforms as he describes, but is at the bottom of my list on sound as a tube damper material.
John and Tubegroover are right about the Audio Research tube dampers. I put them on my Audible Illusions preamp and I was blown away by the improvements in focus and dynamics. At 5.00 per tube this is a tweek you cant afford to pass up. Best 20.00 dollars i have spent on audio.