I don't own one of these. I have an old manual Gammill PDQ-30, no computerization of any kind, just the longest longarm out there.
The learning curve to be as good as some of the quilters you see on You Tube, blogs, etc, is fairly HIGH. It requires muscle memory, drawing skill and a certain amount of stamina to do it for long periods. You also need extra tools if you want to draw things like perfect circles and straight lines. Free motion is easier.
I have a bad shoulder too, and I've actually found that using my longarm is therapeutic for it. It's gentle range of motion exercise, makes me think of Pilates sometimes ;-). Make sure and stretch before doing it.
"Tension" problems come frequently from running the machine too fast or too slow for the motion you're doing. They also come from unmatched needle eye and thread, from dulled needle, burred thread pathway, making your quilt sandwich too tight, etc. You will find people with any machine, sometimes because they don't understand the problems. You will combat these problems with any quilter if you don't take the time to understand how the thread feeds and what to do when the problems arise.
Industrial quilters are expensive. I've heard stories of many that stay unused in the basement or get sold for a song to just get rid of them. They are not for everyone. Go in with your eyes open. Maybe rent one for awhile and see how you like it first.
But I find that mine is a joy. That was not always so. I'm glad I didn't sell it when I wanted to. The newfound patience that maybe comes with age? is what makes me enjoy it now.