I'd love to have a really big long arm, but realistically, that isn't in the financial cards. My HQ16, bought second hand, is a work horse. After 3 years of use, I was going to take it to be serviced when DH said. "Let me do it."
I hesitated, but then told him he could service it (he's handy mechanically), but if it didn't work after he was done, I was upgrading to a bigger machine. That might have motivated him; he cleaned it and put it back together with no 'extra screws'. After taking it apart, the only thing that it needed was to removal of a few pieces of thread that had lodged the mechanics.
The bottom line is that, for a relatively simple machine like the HQ16, self service is possible if you're mechanically inclined.