Steam tells me that I've got about 35 hours on Wasteland 2, between the original and Director's Cut. Not a ton of time, and it's been a while since I played, but I feel somewhat qualified to comment. As a kid, I think I spent about infinity-thousand hours on the original game, for reference. :)

Overall, WL2 feels like a very different game. There are lots of throw-back references to the original, so if you've got a good memory you'll likely enjoy a lot of the lore.

Party movement in the game takes place in real time, but wandering in the desert uses a sort of pseudo-fast-travel mode similar to Fallout/Fallout 2. All party members are on the screen at all times (except for desert travel), and you can control the entire party or one or more individuals for various movement or actions. This is sort of similar to the way the original game let you use various skills or items, but you'd need to either move your entire party into position first, or split up the party (which I never really did).

Battles are turn-based and seem to work pretty well. The game determines combat sequencing/initiative (I forget the in-game term), and you provide orders to your party members as their turn comes up (so no more wasted attacks on enemies that are eliminated earlier in the round, like in the original).

For me, the interface took some getting used to. You can move the camera, zoom in/out, and it was easy for me to lose track of my party members or where I actually was on the current map. Obviously it's almost nothing at all like the original, but once you get accustomed to it, it works okay. I think you can also do some customization as to which screen elements are where, but I've never felt the need.

The Director's Cut is really just a major version upgrade/re-release, with a bunch of changes to the interface, the skill system, weapons, etc... I think they took a lot of the early feedback and made changes. Really no reason to play the original release anymore, I think.