I've had good and (
very) bad experiences with both brands.
Assuming the price difference isn't huge, I'd opt for the Takahashi simply for it's mechanicals and range of available accessories.
Not sure if the Vixen's quad lens design is to flatten the field or reduce colour. If its the former, it could be a benefit if you plan to do a-p as a decent ff will rum around $250+..
Though if I was going out tomorrow to buy an f8ish 4", I'd get a TV102!
