I'm a longtime happy Vanguard customer.
One thing to keep in mind is that for lots of stuff that you want to do, Vanguard has a form that you print, fill out, and mail in. They do not do as many things online as you might expect.
So if, in the process of your transfer, Vanguard asks you to fill out a form, that is probably to be expected but may be a bit unexpected by a new customer such as yourself.