aftermarket warranties are great if you are sure your car is going to break. hopefully you aren't going to buy a car that you feel so sure of it's failure.
a-protect isn't the worst out there, but they are definitely not the best either. even with the warranty, they usually have most of their plans with a high deductible and a max cost per visit... so say you pay a grand for your 2500 limit fix and a 150 deductible...
most of these companies have specific shops they work with and they charge extra (whether you want to call it their cut or whatever) for a job you can do elsewhere... say a transmission job that if you shopped around, you could get done for 2k... they will charge 3k. you think, "well, it's not too bad and it is going to be covered..."
but in reality, you paid 1000 for the warranty, 150 for deductible and then 500 for the overage.... so 1650 paid instead of 2000... not such of a life saver. keep the money in your account for a rainy day and just be smart about where you get your work done.