Do the "pay for" tour guides least busy/optimal park schedules differ from all the free historic park "busiest days" info available? From everything I've read the best days are usually a combination of: go on the historic lightest days that don't have any EMH's or special events that day, and especially if its also the day after an EMH day.
Other than planning your "must do"/most popular attractions for the first few am hours, getting nearby FP's for the next attraction before getting in a standby line for another(ALWAYS have a FP in hand!), and not crisscrossing the parks mindlessly, have you found the tour guides worth their price? I'm up in the air on whether or not to subscribe to one as I've heard differing opinions, many of which say the items I mentioned are 90% of the plan anyway.
Hmm.....well, it depends I guess...how many times have you been to WDW? Do you know the parks and the attractions well? If not, I'd definitely do it. I had already been 5x in the past 2 years before subscribing, so I didn't get a ton of new information I didn't already know, but some of the touring strategies such as which things to do first, or tailored to specific age groups, were well worth it. The various sites will all tell you that the touring plan and order is more important than the park you pick on that day, and we agree, this is true. So is getting there early. It's a lot of information to digest though, but having a quick plan in mind definitely helps a lot. At AK for instance, go hit Expedition Everest or Kali first thing, or the Safari, get Fastpasses ASAP. If you've never been there, you wouldn't even know that.... MK is tough too, especially Fantasyland for little little kids.
If you're up in the air, especially on TGM, I'd say do it, it's worth the $20. There's a DIScount for DIS board members too if you subscribe. Be prepared to spend a few hours though reading the information and printing out the suggested plans there. You only have 12 or so days left, if you have the time I'd do it, if you're an old WDW pro then don't bother, or you spend as much time reading suggestions on the DIS too, for instance.
There's lots of people from here though that swear by it, which prompted me to do it, and I was glad I did, so another thumbs up from me at least!

I picked up a few great tips and suggestions, and I think it was worth it.