D1 and D2 were fabulous FPS games that allowed for SMOOTH and flowing controls in cramped, constricted, and sometimes claustrophobic feeling environments. If there was a need to maneuver in an emergency, it could be easily done with the controls, allowing for a quick escape - without getting hung up on some dumb piece of environment. It was this quality of smooth response and control that made Descent so much fun. Where I feel modern FPS games fail, as did D3 to a certain extent, is the focus on developing over-detailed (in my opinion) environments and surfaces. While they provide a fun "look" to the game, they typically only create hindrances and annoying places for the character (or ship in Descent's case) to get hung up on. This creates a less than realistic gameplay experience (I sometimes find myself yelling things like "Yeah - like I'd really get stuck on a DOOR!" in these newer games), which personally frustrates me as a player.
While I understand the "look" is what some developers use to market and sell games in this day and age, I personally feel that over-detailing environments can cause fluidity problems with in-game character mobility. I think it would be unfortunate to see that type of stereotypical mobility problem introduced into a new Descent sequel, especially for a game that thrives on smooth motion.
If gamesas can duplicate the smooth controls and maneuverability inside those "cramped" environments we all loved so much in the original Descent, yet WITHOUT creating excessive amounts of "catch points" for mobility... I think they will have a winner.
Just my $.02.