I guess $11.00 a month or so isn't too bad. I thought I read a while back they were lasting only about 3 weeks. How much does Baqua cost? I know for a 3 month season for my AG pool it was going to cost $250.00 but I only use about $50.00 in chems a season.
My only problem with "exclusive" devices whether the frog, cover lifters or anything else (and it doesn't have to be only with spas) is that exclusive usually means expensive until the patent runs out. Why couldn't any manufacturer put an in-line bromine feeder into the tub and let people use generic 1" bromine tabs. It would still do the job.
Then again if someone bought it for that feature then the convience and expense should be expected.