I have gone to three or four shows at the Fillmore and have always had a good time. They have plenty of bars scattered throughout the venue which helps disperse the lines - but the lines always take forever. I know it's not unusual to wait in these lines, but when there are five people in front of you, it shouldn't take 20 minutes to get a PBR.
The bathrooms are a concern as well. Obviously lines are an issue, but the last couple times I have gone, there seemed to be plumbing issues with standing water(?) blocking several urinals.
The saving grace of course is the quality of the shows. They always have good acts and a good variety of acts as well. An intimate venue with all the normal issues of a music hall.