Recently returned to HF listening with a RSPduo. I needed a general purpose antenna and after some research bought the Wellbrook rigid loop. I can confirm it is an active loop, as I think are all the Wellbrook loops.
I have only had it for a couple of weeks, but so far very pleased with it. No idea on the performance difference between this and the flexible loop, but probably minimal. Background noise level using a wire antenna drowns out all but the strongest of stations, whereas the loop pulls them in well.