I know you say you have narrowed down to APQS or HQ. Any reason you are not considering an Innova?? I ask only because I have seen a lot of LAers upgrade to Innova. Not only that but at the last MQX in NH my friend and I got right up on every quilt. I am talking nose right up to the quilt. At MQX they say what machine was used on the tag. Of all the quilts we saw quilted on, like A1, Gammel, HQ, APQS etc the stitch quality of the Innova was obviously better. An Innova stitched quilt won Best of Show. I rarely see Innovas on the market used, which means those of us that have them, see no reason to upgrade or part with them. I haven't comparison priced since I got mine a few years ago but back then the HQ and Innova (with standard SR not lightening stitch) was comparably priced and the Innova was obviously a more heavy duty machine with a MUCH better rack system.
I don't want to further muddy your waters, just thought I would throw that out there.