I have these, excellent quality and, I feel, fairly priced. However, for the first 9 to 10 months I did a lot of tube rolling, and over time I ended up wrestling with the fact that as I removed a tube the lifter would become loose as well or sometimes come out (or partially out) with the tube. I remember reading suggestions to slip some dental floss or thread under the lifter or tube to assist but the more I thought about it the less I liked the idea of something that might melt or ignite down in the hole and these sockets are pretty tight so whatever i used it would have to be very strong and then I was concerned about the control over what I was removing as the tube openings are small. Plus, having the pig tales sticking out and laying across the top of the unit was a less than elegant solution / look. The lifters (duh) lift the top of the tube higher above the top surface of the MJ2 making them more of a target.
I then sat down, took my audi-O-C-D hat off and put on the tin foil one. Knowing Schiiits design mentality from reading the book and their posts, would Schiit design any piece of equipment, tubed or solid state, that they knew would shorten tube or other component life? I've never seen any temperature measurements that might settle the issue one way or the other.A tube can fail or get noisy but will lifters prevent those things from happening? I tube the MJ2 as designed and stopped stressing over it.
Again, the lifters are well designed and a solid piece of kit. For the money and considering how expensive some tube pairs can be there's no harm in using them and maybe they will extend tube life and maybe make more sense to me if your not, or are done, tube rolling. Another thought, unless you leave your equipment on 24/7 how many around here hang on to any piece of gear before, what, 10,000 hours of use?
As always, pluses and minuses.