Guaranteed Rate is an excellent lender. They are a mortgage banker - they originate and fund their own loans and then sell them after you close.
I have used them extensively (I'm a Realtor). They are excellent with VA loans too. You are in good hands with them IME. They communicate well. They have a great process from application to closing.
If you can increase your mid-score, you can get a better rate with Guaranteed Rate. Do you have a plan to increase your mortgage score? Quickest way is to pay down/pay off your cc debt. Pay all your cards off except one and have it report a very small balance of less than 9% of its credit limit. Some people report that they have best results with 3% to 5% of its credit limit but each file is different. You should see a big bump in your mid score if you reduce your utilization. EDIT: I realize it isn't always possible to pay off your debt. If you want to post your cc's and limits and balances and the funds you may have available to optimize your paydown, we can give a little guidence.
Congratulations on your approval!
Yup GuaranteedRate is indeed a GREAT lender.
How do i know? They are the lender for my FHA mortgage closing soon