I'm reviewing the arena as a concert venue. I have been here for two shows - Pink's The Truth About Love tour in 2013 and a local radio station's Christmas Rock Show in 2011.
In both cases, I found the experience at Oakland Arena to be quite lacking. Here's why:
Sound quality: this venue is really designed for sports and, as such, does not seem to have great accoustics. Despite some world class acts passing through, my experience of the sound has been that it is not that loud and quite tinny.
Facilities: For concerts, they don't seem to open all of the concession stands. This creates enormous lines - think 20 minute waits - at the stands that are open before the show.
Parking: Parking is extremely expensive ($25-35) and if your show happens to coincide with a baseball game at the stadium next door, you can get caught in really bad traffic.
Public transit: The arena is right next to the Coliseum BART station, which is extremely convenient. But getting to the station can be a nightmare after a show. The overpass on which you have to walk is not wide enough and, to add to the congestion, hot dog sellers set up half way across further cramping things. Once at a U2 concert at the stadium, we ended up in a very uncomfortable large crowd situation just trying to get to the overpass and several people in the crowd got very nervous from the cramped conditions.
If I could find one upside, it is that the seats are actually quite comfy for this kind of stadium - even though I have long legs, I've found I can sit relatively comfortably.