Buying Tubes Again; Maddening

Sounds_real_audio, Can you please explain how a tube is properly respected by a designer?

Just today I had to make the decission whether to buy the longer lasting tube or the better sounding tube. I chose the better sounding tube.

Elizabeth, While various circuits have an effect on tube life some tubes simply last longer than others. While one tube may last only 500 hours another tube may last 2,000-3,000 hours or more in the same circuit. Unfortunately the better sounding tube can have the shorter life.