I have the brother pq1500 mounted on a frame. I’ve had it about 7 yrs and have only had 1 repair. The motor went out about 4 mos ago but it only cost me $150.00 to replace. Eats any thread I feed it, don’t have to mess with tension much (except for humidity in the hot summer months) only downfall is the 9” throat space. If you do a 100” line quilt you can only do about a 3” border since a lot of the throat space is taken up by the finished quilt. You can do larger borders you just have plan on doing them in multiple passes. You roll a lot and there’s is more thought in designs BUT it is very workable. I have the grace SR2 frame which is no longer available but the newer QZone Queen is very similar. They are less expensive than other machines and have the features you are looking for.