That infiniti is a great car. $12k in damages isn't really that much, but like someone mentioned, the sub par paint job is a reflection of their worksmanship.
Personally, my car (impreza) has gone through a few minor accidents, 2 rear ends ($6k repair each time), 2 cars backing into it, etc. The car so far drives the same as usual with no other issues. The paint job and buffing is always done very profesionally. In fact my car looks better than the second year I had it. Remember that if the work was done through insurance, everything will be OEM, and we all know how much OEM stuff costs, and on top of that, from a luxury car manufacturer.
Normally I would say it's ok since it's been checked over and is under warranty, but the paint job REALLY throws things off. It's a luxury car too, you would want to spend as much time with a great finish. The poor paint job could also mean that some pieces WEREN'T replaced but just fixed up and repainted. Again not always a bad thing, but is a factor that may mean something when everything seems to point to them cutting corners.