Well, I'm interested in getting one copy of this score, so if you could please let me know which version you prefer and why, I would greatly appreciate it!
I like them both. It's awesome to have the original Bernstein-conducted film tracks, but in some cases I actually prefer the tempos found in the new Tadlow performance... weird, right?
I too have them both and enjoy them both, but I lean slightly toward the Tadlow recording. The sound is better and there are a lot of extras on the Tadlow.
I also have both versions. The Tadlow is a very good performance with excellent sound. If the original version is woven in your mind as an inextricable fabric of the film you may prefer the LaLaLand.