We actually tested both units, the output is very very similar for NTSC, in fact you can barely tell the difference even on the video essentials test pattern DVD.
I would rate the composite BNC output of the V800 better than any of the NTSC laserdisc players except the X9 and the X0.
Functionality wise (home user type features) the industrial players leave a lot to be desired, but picture quality wise they are excellent.

The only reason to go for a 4300D over the V800 would be if you had PAL discs to watch.