I find this cutter a bit tricky to setup - it's trial and error, trial and error etc. In theory you could experiment and make a table of the height from the table to the top of the cutter for different board thicknesses, so you can setup in one shot with a height vernier or similar. I've never had the patience to do it but its probably worthwhile if you are going to use one on a regular basis. But once it's set, you can get at least one perfectly flush face. This depends on (i) firm hold-downs on the table and (ii) even board thickness.
If its only a couple of boards, I revert to biscuits cos of the faff setting this cutter up. Also, you'll get a funny looking line if you mould across this joint - doens't look so good if it's a table top .
