In my old 319 I never considered it a hassle to change the bobbin, but the 320 is - the wooden base has to come off completely beforehand. After learning about that easy modification (to be able to use 15x1 needles), there was no way on Earth I was going to not do that. There are only two sizes of 206x13 available and neither do stretch fabrics.
I'm with Miriam's DGKs and think these machines are great and I agree that they're undervalued. The reason for the latter must be to do with the needles.