another negative report: maple
Maple ( in bay area) is yet another consultant that fleeces you.
The point to remember is
a) an immigration consultant will NOT speed up process (xthe officials in maple admitted this after some prodding) NOR will they do anything in case your application gets stuck
b) What they can do is be very orderly in the papework. Respond to the letters from consulate in time and so on. However, all this happens only if the person who is assigned to your case is diligent. At times they don't care(heck some persons in Maple can't even speak English properly) or are plainly inefficient (it took them 1 month to tell me that my assessment has been received and that too when I called)
So until and unless you can spare a few thousand dollars - don't go for immigration consultants OR are very bad about maintaining your paperwork , don't go for a consultant.
Instead, go to newsgroups, be very diligent about the instructions in the form, ask people around and apply. Contrary to conventional opinion, my experience has been that advice from immigration newgroups / trackers and fellow applicants is more uptodate then those from the lawyers