I have done quite a few playfield overlays in the past and when done correctly they look as good as the original. However it does take quite a bit of work to do it right. I sand the entire playfield smooth, lay on about 3 coats of clear, wet sand smooth, place the overlay of the playfield, cut out and remove all the faux wood and let it sit for about a week. It is then sprayed with Bulldog adhesive promoter then apply another 3 coats of clear. Wet block sand again to level all the edges and apply another 3 finish coats. After wet sanding & buffing they look beautiful. With the clear finish they play as good/fast as an original clear coated playfields and with the real wood showing they look original. I have seen some repro playfield from Europe that are basically just overlays, not screened.
However I also only use the overlays with clear inserts, also so you can see the true color of the insert.
Below are pics of a MM I did about 5 years ago. Lucky I was able to find a NOS playfield to scan and had small overlays made to cover the wear.

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