I found VI to be waaaaaaaaaaaaaay better than VII. I feel it had a much better cast, better plot, music, etc. It was just a better experience in my opinion.
The strongest thing VI has going for it is the cast. That really is a strong cast of characters, and music-wise there are some of the series' best tracks, but there are a lot of weak links in the soundtrack wheras the entire FFVII soundtrack is the best the series has ever done; period. VI has a good soundtrack, but it really is a transition soundtrack between the older style of FF music and VII's aesthetic. I'll give big points to "The Decisive Battle" as being one of my favorite songs of the Final Fantasy series. That song has special meaning to me because back when I was 12 and started playing VI for the first time I was living in an abusive household with a not-so-nice stepfather (to say the least). It took an outsider to explain to me that I was undergoing domestic abuse, and so I came up with a plan to get my stepfather "caught in the act" of attacking my mother by waiting for the next time he struck her to call my friends and get them to "come over with weapons" and "hold him off til the police come". The plan was for me to call them and them to come over and after calling them call the police. To save time, I made a code word that meant, "It's time. Get over here NOW." The code word was "paladin". Any way, long story short, the song I had in my head when planning that scenario was "The Decisive Battle", so the song has special meaning to me. And for those wondering how it went, the plan was never put into action and we ended up just moving all the shit out of the house in the middle of the day when he was at work and high-tailed it 3 states away from him. Oh, nostalgia.
Anyway, plot-wise, I haven’t gotten far enough into VI to really judge it, but I can say this; in terms of immersion and pacing of the storyline and the feel of the world, VI is actually probably on the lower tier of my list of Final Fantasy games. Honestly, I got into V a lot faster than I got into VI. Just about every other Final Fantasy game I’ve played has a better level of immersion than VI. Don’t get me wrong, I’m really digging the characters and the quirky dialogue, but I’m not instantly caring about the importance of the overall landscape of the game. And to those who may argue I haven’t played RPGs in a while and may just not have that ability, I’ll tell you that I got into Xenogears and, to a lesser extent, XII (though certain aspects of that game make me cringe). I think that VI is much better than XII in terms of, gameplay, music and cast, but XII definitely makes you feel the tension of the conflict much better than VI (at least at this point). And I have no bias against older FF games, as I think that IV is better than all other Final Fantasies excluding VII and perhaps Tactics.
Basically, VI is good, but overrated and people just need to admit that the reason VII is the most popular is because it’s the best. It’s like people who like The Stones more than The Beatles. Yeah, The Stones are pretty good, but come on, The Beatles freakin’ crush them. There’s no comparison. And personally, I like The Kinks better than The Stones (despite still digging The Stones quite a bit). For analogy purposes, VII is The Beatles (the most popular one due to the fact that it’s the best), VI is The Rolling Stones (still pretty cool and something for people who don’t want to cite the more popular one as their favorite but nowhere near as good) and Tactics is The Kinks (underrated and amazingly kickass and probably better than The Rolling Stones anyway).
And then Xenogears is probably Rush or something.