I have one of his fiberglas stocks. It is really heavy compared to the other stocks I have seen. Makes the entire rifle really heavy. The comb is sort of strange, it seems to make the rifle kick more. I'm not sure how that happens because it's heavier than it was before.
I am building a 6br and purchased a stock from boyds. It's a laminated one without the thumhole. It was really easy to get ready for bedding and finishing. I'm not sure which thumbhole from hollands you are looking at but if it is the fiberglass one I think you can do better.