Over they years I've used countless third party accessories such as Speedlites (from Metz, Sigma, Yongnuo), few Radio Triggers (from Yongnuo), Battery Grips (for 7D & 450D), Batteries (from Pearstone and 1 more company I forgot the name), lens hoods, Vello Tripod Collar (for Canon EF 100mm f/2.8 L IS) etc. Every single one of them (with the exception of Vello Tripod Collar) failed me during a photo shoot ... the Metz plastic shoe broke with a simple 1 foot drop, Sigmas just gave up the ghost one day, Yongunos did not fire wireless during a very critical photo shoot of some VIP's, both Battery grips failed after 1 year, batteries had very poor life span, lens hoods split ... but the Vello Tripod Collar is going great guns. I now try to stick to only Canon products as I've come to trust their finish and the R&D that goes into some very minor details that make a difference to the end result.