yes, actually you're right, TSI has very solid clear rock sound

I think the concert tickets are selling like crazy anyway. at least as of 2016 and 17. I can imagine the momentum will start dropping after the current tour goes to its end in november 2017, then it might make sense to do something like that.
but in the GNR world, nothing ever goes according to logic, marketing rules or just simple common sense, so anything can happen.

well, I think there's only one truly good song at HEOL - and it's Into The Fire, which is totally non-mansonic fragile thingie with a beautiful guitar solo (have you ever thought something from Manson stuff can be described as beautiful, maybe except for some stuff from Mechanical Animals, where it was deliberate?). also Devour sounds promising, but I think the teasy-teasy way they did it, which gets anti-climatic right when one expects a powerful chorus and instead it backs off, pisses me off, lol!
and yup. there were some connections to GNR. besides Chris Vrenna, there was a certain guy named Robin Finck who helped working at the very first album (Portrait of an American Family), though uncredited. but that album can hardly be described as a Manson album, it was more Trent Reznor album, using the Manson band as his alter-ego-evil-project... or maybe more precisely said - indeed it was a Manson album (a bootleg of pre-Reznor mixes exists and it's wicked), but only Trent made it sound brutal and modern, his work culminating in Antichrist Superstar which was a huge shock.
haha, for me personally, I only started discovering new music because Axl and Guns were on hiatus and I desperately needed something fresh and new. and then I've discovered Antichrist Superstar and my world has never been the same again

not sure if mid-90's is the right way to start, because all the clasical bands went to crap by that point. music was overran by grunge already, together with alternative rock and emerging nu-metal genre, also with extreme metal on the rise. this was the dominion of Marilyn Manson (and Antichrist Superstar was THE album of the late 90's). you can't just turn back to half 90's hard rock. you need to reinvent it and yourself as well. Axl seemed to know it and tried for a couple of years, until some idiot told him ChiDem is shitty about 5 minutes before it went to release, shit hit the fan and everything went down the toilet.