I had been in the camp that preferred Vanguard over Fidelity, generally slightly lower ERs, but I don't think that is always the case anymore. Fidelity is usually close, maybe better in a few areas.
Some people felt Fidelity provides superior service, but everything I ever needed (not much) from Vanguard was handled easily (almost all online), so I never felt this was an issue.
However, after helping to settle my FIL's estate recently (still a WIP in some minor ways), being able to walk into a B&M Fidelity office was a huge benefit. FIL had some paper stock certificates, plus some stocks held at two different transfer agents. We made an appointment, I did whatever up-front work that was needed (just organizing the stuff, and getting the transfer agent details), and the Fidelity agent got everything transferred and accounts set up and it all went smoothly. They provided the Medallion Signature guarantees that were required, notaries and everything for the transfer agents (those forms did need to be mailed in, but just the forms). Then I just went online to verify they all got credited to the account a week or so later.
This could have turned into a real hassle by mail - where to get the Medallion signature guarantee? Mail the stock certificates, and insure for the cost of replacement (not an insignificant cost), trips to the post office, tracking everything and following up at snail-mail speed. No thanks.
We are in the process of consolidating at Fidelity, because of this.
-ERD50