This Toyokaflex I never heard of, but it indeed looks like a most interesting camera.
I have both a Seagull 4 f3.5 and a bunch of Lubitels I got from poland (lubitel 2 and 166u), some quite old.
The Lubitel 2 is made from a very nice material but finding 27mm push on filters can be a real pain.
The 166 I truly love: it's VERY light, it fits 40.5mm filters, the shutter is dependable and it actually produces very good results. Most of the internet examples sporting blurred photos are probably due to defective samples or to the users not knowing about lens sync on these soviet TLRs. The viewfinder is a bit strange though, it's a plain "brilliant" design from the 30s with the addition of a small ground glass patch in the center to allow focusing (but that takes a bit of getting used to. You also need to place your eye in a precise spot in order to clearly see the image). Never had a light leak into one.
The f3.5 Seagull feels like a old brick, and finding a neckstrap for most of them can be a problem as it uses a weird pin attachment.
The mechanics is sound (expected from its weight). Optically I had results that are difficult to tell from my father's Zeiss Ikoflex in terms of sharpness (we often use FP4/HP5s, so no fancy t-grains). Filter thread's still the 40.5mm, so very convenient. If you're into double exposures YMMV, as mine has always refused to allow me to do so. I don't trust its self timer as a couple of times it jammed the shutter, so never touch it, and I usually set the shutter speed before cocking the shutter, as I noticed the lever (already quite stiff) can get even stiffer after cocking.