I don't have an Overton myself, but most people, it seems, are quite fond of them. I have a Burke low G and would say that it was a very nice whistle for the relatively low price, and I also like my inexpensive little Clarke. I think it is a matter of personal preference. (I believe different people will likely all have different opinions.)

The Chiffboard is sadly down right now, but when it is up again, I'm sure you'll be able to find plenty of other Overton fans. :)