You've used a few of its features since ME3 has been released (a title plagued by countless non-origin related bugs so far as well). I've been using it every day since BF3 came out. I'm not sure who you think has experienced the smaller sample size.
I find its reaction with the overlay to be faster than Steam's, and in addition I love that you can disable origin interaction completely during games, significantly reducing its memory footprint. To be honest in that last regard it is leagues ahead of Steam.
My point ultimately is not that either steam or origin is perfect, but rather they are both sufficient. Origin does a lot of things better than Steam, whereas Steam has the better store front. The existence of Origin is more beneficial to gamers than the minor inconvenience of having a second program on your computer (that auto-launches itself when needed). It provides competition with Steam, in a market that Valve has dominated (digital distribution). Amazon Digital Downloads is providing another source of competition and with the aggressive sales that have been seen on Amazon, and on Origin (50% off a lot of their library this week) that gives Valve more cause to have weekend sales and such more often than they do. You have to remember that a lot of the incentive for Valve to post steam deals has waned over the last couple of years since the service has taken off, since they can automatically push a wider profit margin on any digital ware over the boxed copy that another distributor would have to work with. That said, the more competition in the digital distribution market, the better. At least for the consumer. That alone is enough reason to toss some business Amazon, Origin, GOG, GF etc's way.
A lot of the problems with Mass Effect 3 don't come from the publisher's side of the house. They come from a developer that committed to a date, built a game that in a lot of ways feels regressive, and was designed from the ground up with day one DLC (and don't fool yourself into thinking Bioware is such a benevolent studio as to not push this kind of crap just as hard as EA wants to).