Is it worth a look for an old school gamer?
Yep, I use it pretty much exclusively. But if you're DMing it, you'll want the box set.
I'll assume you've read the reviews. If not, then go here,
Player's Guide Reviews
and here.
Box Set reviews
The Player's Guide itself is really just an overview, with gods, classes, timeline, geographical overview etc. It's a companion piece to the box set, which is where the meat of the setting is. Namely in the form of maps, places, and things to encounter. (And I mean LOTS of maps, places and things to encounter.)
A lot of the stuff in the PG are things I tend to make up myself, so a lot of the history etc goes mostly ignored. (I always draw up a history that supports whatever game I'm running at the moment...sometimes it's an aspect of the Judge's timeline, sometimes not.)
Hope this helps. Check out the reviews, then if you have any questions, fire away. I'm always up for talking Wilderlands...but those reviewers have pretty much said it better than I could.