DT's remakes show a lot of evidence of careful planning for proper clan scene matching and competition play. They usually have a good variety of options for play-styles depending on the kind of clan you belong to and the jumps foster improvements in your technical ability.
The most overplayed maps are the junk you constantly see on pubs like airtime, blitz, shazam33, razzle, etc... Which are simply popular because they offer extremely simple and thoughtlessly quick gameplay. Thats fine for speed servers and whatnot, but I think it drives a lot of serious players away from pub play because its pretty boring after a while. I'm not a fan of er33t or 20id or whatever they are called now, but I can't fault their taste in maps or their knowledge of what comprises tactical understanding of maps like castle1, which are perfectly balanced for in-depth play.
This isn't really the place to be discussing what makes a good or bad map though i guess, so I'll just say on-topic that a map like shock should not be remade. It does it's job as it is: its quick, dirty, great PGP, seems to be quite popular. There's probably nothing else you can add.
- Dagless