I agree with Cathy C to a certain extent. It seems all the manuscripts I've edited for clients either had gaping plot holes, or the writer didn't know where the story began. Being objective about your own writing is the hardest thing in the world. At least, it is for me.
I have two crit partners and love them dearly. The problem I've found with some cp's, though, is that you become friends, and once that happens, no one wants to take a chance on hurting the other's feelings. It can also be a slow process.
I generally turn a manuscript around in a week if I'm able to start on it right away. I often edit a few pages for free so the writer gets an idea of how I work, and whether or not I'm what s/he's looking for, as well as whether or not the work is worth investing my time in. I won't edit a first draft of anything.
I'm happy to tell my clients what works, what doesn't, how they might fix it, and line edit the whole thing for spelling and punctuation. I'm still here to answer questions during their rewriting process. Some take the advice, some don't. Some are published, some aren't.
I'm going to stop here before this turns into spam, but if you hire someone to edit for you, find out what you're getting for your money before you hand anything over. Will you be paying a beta reader to tell you there are problems, or paying someone to help you fix them and make your manuscript as perfect as possible so you can submit it? Find out exactly what you're getting, and you'll be more likely to be satisfied with the end result. Good luck.