Actually they're not being developed by the same team, or at least weren't until recently, considering Reckoning is essentially Big Huge Games' baby (now they've been bought by 38 Studios).
As for the demo itself: with a good art style, better dialogue and an actual professionally-done UI this could have been a killer. Can't really judge on the quest design, since this is really early on, although it seemed nothing impressive unfortunately. In the state it is right now I think I'll wait on a deal. Comparisons to Divinity 2 I think are pretty apt, although comparing the two demos, I think Reckoning's combat is much better and the mechanics in general seem more solid.