I have been running sweep tubes amps for only about a 1 1/2 yrs so am no expert but my family and friends have run them for many years I have found out that sweep tube amps are one of the amps to own they will take a beating and keep on putting the power out and I have not had any major problems getting tubes or parts for them. Tube life seems to be what people worry about the most but alot of amps are still running atfer 25yrs with original tubes and now need replaced that is a good tube amp life as far as I am concerned I know people constantly burning up their pill amps and how many original ones do you think will be in use after 35yrs like my original phantom. As far as driving amps I find as long as you keep your radio or driver deadkey down to 4w or under I run 3w my tubes donot get cherry or orange I have had cover off and watched during a long time keyup. I believe that has alot to due with initial tuning I donot drive my creme and tan phantom much because it puts out so much I donot need to drive it. Remember almost all have owned a sweep tube amp at one time or another and did you really have that much trouble with it?.