Thank you for the link. I saw it a few weeks ago on an Adam board, but forgot about it.
I know,that's the only official release of a QAL concert on DVD. But I didn't buy it,because firstly it's really expensive, only available from Japan and secondly I don't like that particular concert. The concert was shortened, because it was for a festival. There are more than a quarter of the songs of the regular setlist of that year missing. In between those my favourites STL, WWTLF and DA. And since I only came on board in 2015, this concert is even older and I can confirm, that QAL got (even) better since 2014.

This was somewhere around ther 30th concert together, now they have more than 150. So that's natural.
BUT if someone hasn't seen a QAL-concert before, it sure shows you, what you can expect and if you will like it or not. (Or maybe not completely, because at least some of their best songs are missing here.

)
What I do like about this DVD is, that they played IWBTLY and that the quality of sound and video is very good.
ETA: the vibrato: I just listened to the video and I have the impression, that Adam did it to a much lesser extend in recent concerts. (And it is true: without a certain extend of vibrato a singer destroys his voice.).
In the end I would like to add to those, who might want to like the collaboration:
I would ask you, if you get the chance, to jump the gun and just go. Don't think about it too much.
I for one, had never in my life thought, that I would become a fan of an artist like Adam Lambert. Never. Had I just seen and heard him in youtube-vids (or others) I would have thought, he's completely over the top, sometimes screaching (yes, I found it in earlier years after Idol as well) and all in all in his theatrics not always pleasant to watch. I'm sure, that's how I would have felt.
Thankfully, I'm no old Queeny (or old Glambert). Thankfully, because I simply stumbled by chance into my first QAL-concert, without having looked up anything about Adam. I came to see a Queen-concert ( minus Mercury). And in the whole experience of a concert, I really liked what I saw and heard (hey, that's why I'm here). And I think, that's how most people at theses gigs feel. It's great music, a great spectacle, you can see your old heros, also a tribute to Freddie and a capable frontman. And all celebratea big party together.
If you really think, you won't enjoy it, you should stay at home. Nothing is for everyone.
But if you're thinking of it and still unsure, I would ask you to try it. From all the reactions I've seen at my 5 gigs, the chance to regret it, is slimmer than the chance that you had a great time!
Just look at the reactions of these fans in Japan. I think they had the time of their lives, even if some of them seem to cry a lot.