Regardless of their test pressure and of what Big Gas say, they were and still are the best filter as far as catching magnetite and cleaning it. I too have one on my own house and i have all the others in stock so cost is irrelevant as far as i'm concerned.
Build quality magnaclean is the worst alongside the TF1. Plastic container dubious valves splitting magnets. Magnaboosters and Sentinel system filters are brass bodied but as for cleaning them who can tell? You certainly can't see inside them so do you trust the manu's (don't be silly)!
Have you ever tried washing the magnetite from a magnaclean without removing the sleeve? Don't work too well does it.
The whole problem with magnacleans and TF1's is the choose to get them manufactured in china or eastern Europe for the lowest possible price. Quality is second place. This has cost Adey as fitters have changed to more reliable filters. Although i personally have a magnaclean fitted to my system i would NEVER fit one to a customers. It is not worth the risk.
Never think because it is old technology it is obsolete. Look at the Sterling engine which was patented in 1816 but may have a use in future modern day living.