The loan-to-value point needs unpacking. Are all lenders being compared using the same purchase price, down payment and mortgage amount? If one quote falls into a different tier because of how the amount was entered, you may be comparing two scenarios rather than two lenders. Ask each lender for...
I would not put much weight on a promised response-time number by itself. A fast generic reply is not necessarily good service. Ask who answers enquiries, what information is recorded, how viewing feedback reaches you and how quickly serious questions are escalated to the named contact.