IME Wells Fargo is a waste of time and energy. A huge percentage of their loans "pre-approvals" don't close (at least in our area). Not because of the buyer, but because Wells Fargo has a process that is unusually long and some of the loan officers don't even collect the proper paperwork until you are well into the process 30 days or so!
If you go with a mortgage banker in your area (a mortgage banker funds their own loans and then sells them) you end up with a much smoother process. The LO's know what they are doing, they are generally more experienced than the big box bank's application takers and they can broker the loan to any number of lenders too.
Selecting the right lender is critical to making the process a pleasure or a nightmare. If you are going for a loan, if the loan officer doesn't ask for all of your documentation right up front at the first appointment before he issues the pre-approval or PQ - run away and find one that is experienced and knowledgeable. Good luck 
Edit: You don't have to "meet" physically (the post above sounded like a physical meeting). If you can email your docs to the LO and talk to him/her over the phone or email its the same process. The main issue is the lender needs all the docs to make a final decision and a good loan officer gets your docs up front so you have the right info from day one. Yo-yo approvals happen when the lender issues a PQ without enough documentation. You shop for the house and then get turned down for the loan. That doesn't happen when the lender has your docs from day one (unless the lender is incompetent)