Steve's being a bit generous there. Well very generous actually:
Yes I've got one, and yes, I'm working on fettling it. But I haven't finished it yet as too many other things have got in the way. I do intend to 'publish my findings' in due course though.
Broadly:
Most people take one side of the dust hopper off, to allow dust to get into the main body of the saw. This is probably a good idea and was done on mine before I got it.
The mechanical design makes anything by W. Heath Robinson a 'must have' purchase in comparison. "But they're all like that sir", in that price range. Aligning the mitre track and fence with the blade is next-to impossible unless there's some special tool I haven't got! That's one of my mods in progress.
Another one, which relates to the motor plate, is fitting dome headed or straight Allen screws instead of the ordinary M8 ones that hold the motor on. This improves the belt clearance and ease of adjustment, as you can't really get a spanner on the hex-headed bolts with the pulley in place, because there's almost no clearance, never mind ease of access when it's all assembled. It's unlikely to cause problems in use, but very easy to do damage when adjusting the belt tension.
I'm working on a better riving knife mounting too, which will stress the rise-fall mechanism a lot less, and possibly better height and parallelism adjustments for the sliding crosscut table, as that's a bit of a PITA as well.
Oh and if you want to use thin-kerf blades, e.g. Freud, you'll need to make a new riving knife. That probably also means a new SUVA-style guard, as it's mounted on the riving knife.
I might also alter the tilt arrangements, but I haven't thought that one through yet. I won't know until I've got the trunnion issue (parallelism) sorted and can do some proper measurements.
But as I said, my guess is that all saws in the same price bracket have similar issues - I don't think the Kity 419 is uniquely challenged. I'm sticking with mine as I think it can be made into a jolly fine saw, albeit 8" blade.
Regards,
E.