Joined: Aug 2010
Posts: 12,711
Likes: 2,100
From: Madison, WI
Bikes: 1961 Ideor, 1966 Perfekt 3 Speed AB Hub, 1994 Bridgestone MB-6, 2006 Airnimal Joey, 2009 Thorn Sherpa, 2013 Thorn Nomad MkII, 2015 VO Pass Hunter, 2017 Lynskey Backroad, 2017 Raleigh Gran Prix, 1980s Bianchi Mixte on a trainer. Others are now gone.
I built up my Lynskey (full size bike, not folder) with rim brake on front and disc on rear. Front is V brake with a Travel Agent to convert road lever cable pull to mountain bike V brakes, Koolstop Salmon pads. Rear is TRP Spyre with full length compressionless housing.
In dry conditions, I can't tell the difference between the braking power on the front and rear.
In wet conditions, the disc is much more effective than the rim brake.
The rest of my bikes all have rim brakes that I am content with.
Exception, I have a 60s vintage three speed bike that has drum brakes that I occasionally take to the grocery store. Those brakes are not very good.
If you are content with the rim brakes on your folder in the conditions that you typically ride in, keep it.