Infiniti quality is good overall here
There are a few ways of rating a car dealership. For me, I leased then have had the car serviced for the last 3 years.
The car itself (G37 Sport) is awesome. I probably limited my irritation when I bought by knowing exactly what I wanted and then taking my time in the negotiation process. Otherwise, it probably would have been a pain as it generally is when buying/leasing any new auto.
The service has mostly been good. That is, when I take it in, the work is done well and at reasonable prices (Infiniti is more of a luxury and it will generally be more expensive). The only irritation is that the service guys seem to be paid by some commission structure. While most don't pander to you, there's one or two who sort of do ("call ME when you have a problem with this"). Why would I need to call one of them in particular??
Overall though, it's a good experience.