They can be. It depends on how fast you move from one part of your quilt to another and how large a quilt you are working on. I have used home made suspension systems for years and sometimes I find them to be very helpful and other times they slow me down because of needing to stop and readjust the clamps. My current system for my Sweet Sixteen consists of two of those L shaped poles that dog groomers clamp onto tables, four bungee cords and four clamps. I use it when I'm doing dense micro quilting on very large quilts. Otherwise, I find that it really slows me down to have to stop and readjust my clamps whenever I want to move to another section of my quilt. Something like the weightless quilter with the flexible poles might be different- hard to say. You might want to try some out if you can find someone who has one set up.
Rob