I thought eddie only used his 69 SL marshall on pretty much any recording that sounded any good. I think he used the soldano around the f.u.c.k. album, but I dont think you can say that it sounds better than the tone of the fair warning album. Contrary to some I dont beleive eddie ever recorded with the 5150 !
My biggest beef with the mesa is that the fx loop is pretty naff, and the different channels react differently to the same effects. If you want the same delay on channel 1 as you do on channel three you need 2 delay pedals to make it work.
I think it also lacks that killer punch. I sold my 5150 to buy the Boogie, but When i play back the recordings with the 5150 compared to the newer stuff with the boogie, the 5150 just sounds better (same studio same engineer, same guitar)
Also i just could not get the mesa to stay clean, it kept breaking up, but in a really unmusical way, that really grates on the record, kind of like when youve maxed out the pa, basically the clipping on this channel sucks.
So thats the reason I considered going back to the 5150, I thought about the jcm, because ive got loads of od pedals, and i thought the raw power/crunch and clipping would be superior to the 5150, (and it would be a lot quieter) plus it kind of feels a bit shitety to go back to an amp youve sold, without trying anything new. I always stayed away from marshall in the past due to the fact that I had a les paul and long hair! Although the hairs short now so I guess it might be ok!