There's an incredible difference. I think the main thing is most people record clips at close to "bedroom" volumes. If you're not cranking up the amp, you're not going to hear much of a difference in power tube saturation....because there isn't any. I tend to find that the people who say they don't hear much of a difference aren't in bands. In a band situation when you've got the amp cranked up, the difference is incredible. Just different brands of the same type of tube will sound incredibly different. At least to me, power tubes are just as important as preamp tubes and have as much if not more effect on your tone than preamp tubes.
) and has that scratchiness on the palm mutes - hopefully that's not inherent to the amp, guess I'll just have to get one and see for myself! 
