Been around for quite a number of years, only have experience of their 28mm d-slide carb, have a couple of the power jet oval bored 30mm carbs which I suspect may be the copies
Early versions weren't known for having great quality chrome on the slides but I haven't had any problems
Main improvement with trials bikes over keihins that have been noted worldwide is less fuel out of the overflows when hopping. I picked up 1 of the clear floatbowls which is quite helpful & really cheap