Beautiful gun. Mine is a flat rib. Have shot the supersport and the advantage but they didn't appeal to me. Mine has the adjustable comb as well. This may be one of the gun's few weaknesses. It should be micro-adjustable, but is a P.I.T.A to make fine adjustments. Don't discount the plain receiver with the gold F3. It commands respect and is instantly recognized by others. The manufacturing precision is unsurpassed and the brilliant in line ignition system doesn't exist anywhere else. Striking contrast in the wood. I like it.
Don't ever downgrade to a K gun. There are more expensive guns than what you bought- but there are none better.
I have the Vantage with the Supersport stock, so I ended up removing about 3/16" from the comb to get it to fit me. I also have a K-20 three barrel set, but I do prefer the balance and feel of the F-3. If I had purchased the F-3 first, I would have just added barrels for the F-3 , and would have never purchased the K-20. I bought my F-3 out of the Vancouver Town Post of all places, with about 1000 rounds fired, for about half the price of a new Vantage.