I think CF would be better off with more areas like ST and not just one.

I don't like Hell Trips because it's way too confusing to have a large group, it's hard to role-play or you get people who over role-play, or you get the little kids trying to have fun and telling stupid jokes that we all used to giggle and laugh at and you end up missing a LOT of the area. If you aren't leading and looking, there's no telling what little cubby holes with shinies in it that people just simply walk by. Sometimes when in large groups like that I just turn on a movie and put it in the upper right corner and end up watching/listening to that just to keep my attention.

The ST is an area where I can go when I have no PK range and nothing better to do than to spam spells/skills/sups to perfection that I very seldom use AND I get explore/observation XP which is cool to me because I like to try out edges and see what they do. The extra bump I get from that area is worth at LEAST one try-me edge (which also caters to the explorer mind).

I think you would get a lot of bang if you released two areas in tandem that catered to the group masses and the individual explorer and were still puzzle based. Solve the puzzle, tiamt-like creature bowls out of the ground and all hell breaks loose. Pleasant field turns crimson as blood zombies rise up from the ground and while you fight the big bad ass, it scatters the party into the little runts making it difficult to keep the party together and making it one hair-brained exciting time like raiding the palace against 5 opposers. A bunch of little fights break out. The PCs win and get the shiny gem needed to power the gate-room machine and go to the next level. Which would make these "make hell good kosher" people happy because then they'd have a place to take their massive fort horde to and get shinies. You could even have it so that one of the rewards is an alternate way into the depths of hell passed the "non-purity part" and in the process maybe reducing the time it takes to actually get down there to something managable in today's CF.

The ST is a place that's hard to really take a large group in and wreak havoc on things without having long term solo punishment. Plus until you solve certain puzzles, it's generally unfriendly to certain classes to begin with. But then, that in turn increases the reward for doing them, or the insansity of trying in the first place.

So my vote is bring ST back as much changed as you want (I personally don't care if everyone knows the secrets because it's a get out what you put in type place anyways) AND make another dragon-lair type place that is on the order of the Tower of Trothon in size but holds more shinier shinies and some different puzzles, or gives a way for said group to get into the deeper parts of hell faster thus making it useful for goods and evils alike to visit.