I have two of these, have been using them for over two years. I do not use the roller frames that came with the two units. All my stitch pieces are tacked onto wood frames as I like to work on taut fabric. The top piece with the hand screw tightened securely hold the wood frame as I work and it is a quick unscrew of the stretched piece I am working on when I wish to hold the frame in my hand as I stitch.
I believe I read somewhere one is suppose to flip the piece up for getting to the back of the stitched piece for starting/ending thread. Suppose that would work well if my eye sight was better, but I have to unscrew, flip the work over and run my thread behind to start/end.
I have not understood why, but my sister try one of these and greatly disliked it, returned her unit.
For myself, I greatly like being able to put my thighs about the upright area, sit back in a recliner and stitch away with my two hands free to work the stitching.