It had but to me that was just the normal "not-taking-care-of-it" result inbetween tours. He sounded pretty shit on some 2009 shows as well.
On the 12 12 12 show his tone was remarkably clear for that era. And he seemed pretty sick on the first 2013 shows, so I don't think his decline was more than just something based on factors like age - until Richie bailed.

I used to think age plays such ain important role when it comes to the singing voice but there are so many older singers out there who still can belt out the notes, I'm not so convinced it's the case with Jon anymore. I posted some articles in the other threads with medical info on how stress influences the singers and it has a lot to do with what's happening with Jon these days. His voice hasn't been perfect for many years but it was never as dramatic as now... it's hard for me to even criticise the guy for his 'shit' voice because I can sense it runs deeper than most think.

I wish Jon and the boys would have played this song more often live. It was big, only was played once and was not well the performance. I wish there had been more times in the repertoire of this tour, which would have been something great over time.

There is a bunch of songs performed once or never but do we really want to hear those with Jon's current voice? Srsly? Wishful thinking and pretty unrealistic to say at least.

I think that's why rolo said "wish they would have done it more often".
Close to no rarity can sound good nowadays but pretty much all of their catologue could've sounded quite pleasant back in 2010.

Acoustic rendition of STBI done by Bounce:

The vocals are insane. This makes me wonder how awesome a rendition like this could've been in 1995/96 with Jon's and Richie's harmonies. This song is simple in its structure, yet so incredibly good!

^ I ADORE this song so much it hurts! I actually have goosebumps, belive it or not lol

And yeah, just a few years back it was all doable...

Agreed. And Bounce is a great band (never had the pleasure of seeing them live though, since they don't seem to come anywhere near Berlin), but still I find it awkward that the singer doesn't try to imitate Jon's way of singing more closely. I mean of course he cannot have the same voice, but his accent is totally different, he's sometimes sound like a "metal" kind of singer (sorry, can't describe it any better), when he absolutely doesn't need to. It's what's putting me off, to be honest. If he tried to sound like someone from NJ, and a pop/rock and not a metal singer, it would be even better than it is! Much better actually!

I agree to a certain extent, but they all speak so much "Hochdeutsch" that I just think they can't imitate accents in any form. Plus he is much more of a Metallica than BJ fan, so this might to lead to him sounding more like a metal singer. However, his voice has mellowed out a bit in 2015 and since he has changed his singing style there it's not that metal-like anymore.
Yeah they seem to skip these parts on every tour. I know they played Berlin in 2009, but other than that they haven't even touched that region. Maybe the demand isn't there, I'll ask them next time around ;)

At 4.32 David states that he came up with the Livin' on a Prayer riff, interesting.