Saw the artist posting somewhere - not sure if it was in this thread or on Facebook - that the character artwork went through several iterations and ultimately ended up the way it is based on band input and their final approval. Doesn't bother me at all and way prefer it to photoshopped photos on the playfield.
Ed also mentioned in the podcast that he provided musician related input to the artist as well - he said something about the spacing of the frets on the guitars as an example. I'm sure the guitars on the sideart will be fixed by the time these are on the line, especially since one side already seems to be correct.
Now that it has been a few days and I've looked at the playfield artwork closer, there are a few things that kind of bother me. In particular, I don't really love those 1 2 3 inserts all over the place. I believe they are combo related - I guess the 1 inserts light first, then 2, then 3 as you hit the combos. Seems like a lot of randomly placed numbers on the playfield and hope they serve more purpose than that.