you're a tad younger then me no? which version of T.E. did you actually visit? (if any)
2007, 2008, 2009, 2010. I went to Energy 2011 too (with Avicii, Hardwell. It was different). And also all ASOT's except for ASOT 950.
I feel like ID&T with TE had slightly more love for the older 'classic' trance. They programmed classic stages even. And they supported the scene generally better imo, with for example a trance.nu hosted 'future stage'. Also, the line-ups were usually balanced, with lots of ID&T-BeYourselfMusic catalog artists, like Johan Gielen and Rank 1, Marcel Woods. But there was room for the whole scene. It wasn't a label-party. The audience was very international, young (or at least diverse), and trance-minded.
With ASOT, it's more Armin-Armada-ASOT focused. The audience is less international, older, and also less trance-minded. They come for Armin, eventhough they don't know what Serenity is, or Sail. They never heard of that. It's even worse on Armin Only events though. Filled with people who never heard of Shivers and Communication... it degrades the experience for what I consider an actual Armin-fan (well... not so much in the recent years....)
Music wise ASOT sees music like Benny Benassi Satisfaction used in sets. Or MaRLo type of hardtrance versions of what we used to conciser as commercial cheese (DJ Dean - It's A Dream, but then a modern version). I don't know, but on TE audience would simply not accept that crap. A deejay would be slayed online if he played Alice Deejay - Better off Alone in a set during "the holy event" TE. It was different. I remember Paul Oakenfold playing in 2007, he was disgraced on forums, because he played Jackel & Hyde - Frozen Flame (a jumpstyle hit that year). And that was simply not-done. There was more respect for 'our genre'. You can call it close-minded too. But I like to see that in a more positive way.
I'm exaggerating a little bit of course. But I've always believed there was a little difference in it's vibe between TE and ASOT. Of course, time itself did not help. Phones and making movies all the time... that sort of stuff simply didn't exist much untill smartphones came around. The "age of the selfies" made it worse regardless of it being ASOT or TE. And trance just became less popular, which might explain the age thing I wrote about...
The ASOT 1000 classic-party (the friday) though, was great. An almost TE-like party.