Is upgrading stock tubes standard proceedure?

I'm just wondering if I'm the last guy to realize just how enormous an improvement can be had by upgrading stock tubes to NOS. Most of my system has been in place for some time now and I've sought to improve it's performance by tweaking. Tube changes have resulted in noticeable but subtle results; most of the time involving trade-offs... until now. I just upgraded the 6922s in my cj Premier 17LS to Amperex 6DJ8s with stunning results. I can't find any trade-offs, everything desirable in audio is improved IMHO. This is the kind of improvement I would have been looking for if I bought a new preamp and spent twice the money. As much as I've read about tube rolling, based on what I'm experiencing now, there isn't enough emphasis, especially by professional reviewers.

So, I guess my purpose in writing this thread is two fold:

1) Why don't tubes receive at least the same attention as the equipment they're in.

2) Just a heads-up in case there is anyone else out there who thinks they can't justify $100 or more for a small tube.