I too, have been paying very close attention to Axl's vocals throughout these shows.  I think it's common sense that it all boils down to needing more rest in between gigs, and that is just not a luxury afforded to Axl with AC/DC's schedule.  I am sure he is doing all the things he has learned to do to rest, recover and "heal" while on a two or three day break.  He has sounded absolutely amazing 99.9% of these shows.  It really has just been over the past two, maybe three shows that one can notice some strain and/or vocal changes on certain songs at certain parts.  Especially on the Back in Black songs like Hells Bells or Shoot to Thrill.  Not so much with the Bon Scott era tunes, if any at all.  They actually allow him a break.  Hopefully he is not doing any damage to himself, as that would clearly suck for the upcoming Guns tour.  He does seem to fall back on the "mickey" way of singing whenever he is feeling strained.  He is actually quite lucky he has that option.  Brian Johnson did not! He would simply sing down an octave.

Chris Pitman was the "appendix" while he was in GnR.  You could live with him ok, but you most certainly could live just fine without him!  He is not missed.

My first post here, I LOVE how Axl sounds with AC/DC!  It's freaking awesome!!!  Take nothing away from Brian, that guy gave his heart and soul to that band all these years, and sang that harsh vocal style night after night.  That has taken its toll as it would on any singer, regardless of any hearing issues.  It's just a very abusive way to sing. Look at Tom Kiefer from Cinderella and all the problems he has had.   Axl has had vocal issues, as is well known.  Back in 2006, he lost his voice before some shows and Sebastian Bach helped him out by getting with his doctor and/or vocal coach.  I certainly don't know all the details, but Axl regained his form rather quickly.  Axl is a perfectionist and will do whatever it takes to perform at the highest level.  He would have never offered his services to Angus and the gang is he didn't know he could sing those songs.  What's amazing is he gives you the best of Bon Scott along with Brian Johnson. He sounds like Brian did in his prime!  I've listened to the three concerts he has done with AC/DC and he is getting STRONGER, in my opinion.  I honestly bieleve he will finish these shows with them in great form and be all the more ready to hit the tour with GnR, who I will be seeing on July 12th in Pittsburgh.  If anything, this experience will prepare him even more for his bands tour.  Yes, time catches us all and takes its toll.  No matter who you are.  But he has really got his act together on many levels.  I like what I'm seeing and I like what I am hearing.  I hope he does record new material with Guns soon!  I am also not opposed to him recording an album with AC/DC should Angus ask him to do that.  Why not? What a great honor for him.  All the naysayers who are judging him from his past, I get it.  Easy thing to do.  But he is not going to blow this, no way, no how.  And I agree, seeing Guns with any other singer besides Axl, I couldn't accept that real well.  But AC/DC, like Van Halen, are one of the few bands who has made smart decisions when it comes to replacing their singer.  Angus is no dummy and neither is Axl.  If it rock and sounds amazing, go for it!  GnR and AC/DC are my two favorite bands.  I feel bad for Brian, but I am loving what I am hearing from one Axl Rose.