Nothing wrong with magnaclean filters imo, very good infact. There are loads on the market now and the price should be going down. I think worcester advertise there filter having the strongest magnet? who knows? who cares? its about the amount of crud it stops getting to your boilers water ways thats the most important things not what power the magent has.
Ive cleaned a number of filters on service and some dont seem to pic up mutch at all, most magnacleans seem to pic up loads, but then that depends on the systems conditions tbh.
the trappex filter has got good reviews from members on here that have used it, so i would say its probably good. the proof is in the pudding so to speak. We will know in 3-5 years how good all these new filters are as we will see which ones last and protect the boiler best. As we all know plastic and high temps dont mix well over long periods, so how long they last will be interesting and can be taken into consideration when choosing one. Afterall i would want mine to last the life of my boiler.