Back in the day I bought a case of Knecht/Mahle (disremember which brand) filters and went through them in a few years. WHen that stash ran out I switched to the hinged filters, they are easier to wiggle in and out. And supposedly the hinged end-plates in the middle make the filter less-crushable from overpressure. Supposedly.
HiFlow filters aer good-- I've dissected one and can vouch for the construction.
'73 R60/5 Toaster