I have been to BW facilities in Europe twice. Both were bad. The first one was near Stuttgart Airport (STR) where their restaurant was unable to serve a WARM cordonbleau, even after 3 complaints! (It was really still frozen in the middle).
I just returned from a stay in the Best Western Hotel Le Lido, Belgium, close to Brussels airport (BRU). Neither at checkin nor at checkout there was english speaking personell, which I would expect at a hotel 25km away from BRU. The info map on the room said food could be ordered in the lobby or bar and would be brought from a nearby restaurant. When trying to do so the answer was: "Sorry we do not do so, please go to the restaurant yourself."
The checkout was the worst I have ever experienced. It was impossible to make the checkout guy understand I need to have my company's address printed on the invoice. The first printout contained no customer address whatsoever, but was on the hotels paper. The second try, after a long while trying to fix printer problems, was on blanko paper, containing half of my address, the rest was outside the printable area.
IMO BW can not seriously be compared with HI-group, Hilton etc. because it is more inconsistent than the others.
P.S.: One positive example comes to my mind: The Best Western Hotel Plaza in Pescara, Italy: Good rooms, good restaurants, good service.