There are some differences you notice in application but the high quality marine brands all seem pretty good.

The soles are solid wood and were not previously varnished. I cleaned (they were almost black) and sanded them and then coated both sides. I probably put on a half a dozen coats on the topside.

The reason I did it was to seal the wood to keep the glue joints strong and the wood stable to minimize movement from moisture. It looks better bright too and reflects morelight below. Also, wood can pick up odors from mold and I think it helps things smell better below coating all sides.

While it's matt finish (from foot traffic) now, it was gloss originally. The varnish is still doing it's job protecting the wood with no areas worn through. It has plenty of grip for me in our boat.

If we lived aboard, it would require recoating more often I'm sure but it gets alot of traffic in season.