It's got a number of very good details IMHO. I watched it recently, after reading the book, and certainly enjoyed it more than the director's cut. A number of things are explained better and I didn't find it drawn out at all. Heck, I watched it with my mom and dad in the space of a couple of days during my vacation and they kept asking me to keep playing it (and they had previously seen the director's cut too)
But my advice is, if you REALLY want more Das Boot, read the book. Out of all versions of Das Boot, that one is still the most outstanding and will give you the most interesting details. Get it first and read it. Then if you really end up liking it, get the un-cut. It's much closer to the book and you will find many more of the details that were in the book but were not in the theatrical/director's cut version.