My last gutter vac I owned for 4 years, always used the filter, was still working perfectly but sold it as wanted something a bit more compact.
Newest vac decided to use without the filter as has so much more power without, approx 2 years after purchase both motors burnt out.
Honestly, I will continue using without the filter. Vacs work so much better without them and gets the job done so much quicker. I changed the motors myself at a cost of £250 and am happy to do that every couple of years if it makes my life easier.