I was about to respond with the same. Descent: Underground doesn't look or feel like a Descent game. Yes, i realize they haven't had a chance to really work on the movement or combat yet, but the areas don't give off that claustrophobic and directionless vibe, the ships look like submarines rather than a proper Pyro (even if this is a sort of "prequel"), and all those additional gameplay features (tech trees? tunnelling???) make it look more like Miner Wars. (And Miner Wars was no Descent.) I somehow doubt they'll even have any advanced movement, like chording. (It won't appeal to the new target audience.)
Sol Contingency, meanwhile, looks fantastic, seems to play like its Descent lineage (more like D1/2 than D3, from what I hear), and . . . was taken down by a Cease and Desist from Interplay because interplay preferred to give the license to Descent: Underground. (Probably because big names + successful Kickstarter = better exposure)
Fortunately, the Sol Contingency will just remove the infringing art/sound content and release the game anyway, but it's still kind of annoying.
Sol Contingency as it was over 1 year ago:
https://www.youtube.com/watch?v=avPeGfIQnw0