I researched this thoroughly this year. Vanguard is a pain in the ass. No inbound rollovers allowed. Only mutual funds (not stocks/ETFs). Huge 100 page application.
Schwab has been a piece of cake. 10 pages or so of docs. No fees. Accepts inbound rollover from corporate 401Ks. Fee free trading in Schwab ETFs - SCHB, SCHF lower expense ratios than Vanguard.