My experience on a couple of loans with American Sterling was very good. Underwriting was faster than many lenders... partly because they aren't giant behemoths like a national bank or big lender.
They also were one of the last lenders willing to underwrite certain loan products that Fannie Mae and Freddie Mac eliminated this year. That's where the question about "reliable" comes into play... the mortgage industry is going through massive changes - basically rolling back guidelines and credit risk to the more stringent levels on the late 90s and earlier.
Many borrowers have been left high and dry becuase guidelines changed while their applications were being underwritten. A rate lock can provide some protection, but right now the attitude of most investors in MBSs (Mortgage Backed Securities) is that only the simplest, "vanilla" risk is acceptable. It's not the lenders' fault, and they have little control over investors changing their minds, so to speak, with little warning.
I have a mortgage broker that deals with many banks I could check with him and see if he knows anything about them. Feel free to contact me and I will try to gather some more information for you.
Are you shopping for a home loan?