I'm a bit of a transit geek, and while I'm nowhere near as hardcore as some people, I do know that OC Transpo has made some questionable decisions on bus selection. The old Ikarus articulated buses, for example, had to be cannibalized to maintain them, then couldn't even be given away once decommissioned (AFAIK they may still be sitting in a field somewhere). Then there's the buses they bought in the '90s, whose windows only opened at the top because the buses came with air conditioning, but the A/C had been irreversibly removed as a cost saving measure early in their lifetime, resulting in some very uncomfortable buses.
More recently, OC Transpo bought 365 of the hump-backed buses in the 4200 series starting in 2004, and is one of very few transit services to have bought the now-discontinued model, meaning parts will likely be in short supply when it comes time for their overhaul nine years after purchase. The three double-decker buses it recently purchased (with the possibility of buying more) require a whole new garage to be built to service them, because three axles fit in the 40-foot frame instead of the usual two, and thus three lifts are needed--not to mention an extra-tall garage door. It was recently reported that OC Transpo does not have a garage that is licensed to certify buses for their safety inspections that has doors tall enough to accommodate the double-deckers. The inspections will have to be outsourced.
Oh, and did you know that the articulated buses in OC Transpo's fleet have four-cylinder engines, instead of the more popular six-cylinder option? That'll also hurt your resale value (as will the windshields popping out only a couple of years into service).
All this leads me to believe that OC Transpo doesn't properly test buses before selecting them.
The following BBC video shows some thorough testing of different styles of buses available in the UK. The test takes into account passenger comfort, accessibility, and speed of service. The test was also conducted on a closed circuit, to avoid casualties to cyclists and pedestrians.
OC Transpo, I hope you're paying attention.