Can't say for sure. I listen to my VTL's with the cages off, figuring the more air circulating around the tubes the longer they'll last. That's probably just one of many misconceptions I have about electronics. My bet is that it has no effect on tube life. In my room nobody ever goes near them anyhow, so I'm not afraid of damage. As for sound, I imagine the louder the level the greater the chance of some cage rattling, but, again, I might have just made that up. Now for the real reason to listen without the cages: it looks cool.
