MV,
Of the three flight sectors I have taken with BE in the last two years, 2 were operated by 146s / RJs, despite being listed as Q400s in the timetable. On both occassions, there seemed to be a "busy Q400 worth" of pax, which made the 146s look quite empty.
Finally got to try out the Q400 on new year's eve.
Don't know how accurate my sampling is - based on my personal experiences, BE are the most unpunctual airline out there, but I know that not to be the case in the broader scheme of things!