Some like it. If you do plan to buy it, do it before your trip as it is $50 more once you get back from your vacation. You should buy it one week (at least) before your trip. If you do decide to get it during your vacation, it won't contain all your pics (so I have heard).
Do make sure you stop often!!! The more places you stop for photos, the more pictures you will have. Also, do make sure to also take your own when possible. We have went for the past three years and a row and you get to view your photos whether you buy it before hand or not. Disney sends lots of emails after your trip to go and "view them, buy them". I have noticed with each and every trip there are several missing. This year is was missing one of the princesses and also when we went for Woody & Buzz meet in greet the photographer was unavailable. So don't forget to take your own with you at all time and take a few of each important spot/meet in greet.
We purchased the pass the first year and only bought a few select images from the past two trips. Or maybe the first year, they had photo pass and we got that. I still don't know what the difference is between the two. One you get a hard copy cd for extra $$, something like that anyway.
I have only seen a FW photo photographer once so don't count on many if any taken at FW.