What people fail to realise, is that New Vegas was (supposedly) buggy for two reasons: one, it used an outdated engine that was already pretty damn buggy, and two, Bethesda really dropped the ball when it came to the deadline (let them delay it longer, if it means more testing!)
So now that that's out of the way, I think there would have been fewer followers, but they would have been much, much more memorable, and I feel there'd be harder choices to make when it came to things like the Dark Brotherhood ("No, I'm not killing that 'guy on the boat', thank you very much!" for example).
However, while Obsidian is better at writing, they're worse at level/world map design.
This is so true...
Some key people at Obsidian worked for Black Isle back when masterpieces like Fallout and Planescape were created.
The real problem of Obsidian is resource management.
While It's true that some of their projects suffered from being time constrained (the worst example being Kotor 2) this is, unfortunately, a standard practice in the industry. Key dates are usually set (or changed) by marketing or, even worse, by "beancounters" so that results will go into a certain fiscal year; this is usually done to even cash flows and give investors the impression of stability.
A good management should be able to set priorities and divide the game into "compartments" so that any late, imposed changes in the schedule doesn't affect the overall quality of the product.