I have a 4a as well, and I like the way it handles. However, mine has some frame-spacing issues, which I understand is fairly common and possibly fixable with an adjustment of the screw and/or lubrication of the gears under the take-up spool "fork". I have the J-8 and J-11, and along the way I've also picked up the Soviet clone of the Zeiss "turret" viewfinder, so I can now go for the whole "faux Zeiss" look

(yes, yes, not really a "fake" and all that history business, but "faux Zeiss" just sounds cooler )