If I find I do not like the UF configuration, do I have any options to replace the stock with a more conventional one?

You'd have to replace the rear trunion with a standard one. The rear of your receiver will look like a slice of swiss cheese. You could always sell it or buy/build another with a standard stock. Personally I think everyone should own at least one underfolder. :)

Not really.

The UF rear block (some call it a trunion, I call it a block <Slingblade ref there>) has huge holes in it, and boxes in the back of the receiver.

You would have to remove it and re-build the rear of the trunion. Lots of technical welding, and if it's not done right it will look terrible, and/or warp the receiver.

UF's are worth more, so if you don't like it, sell it, get the one you want, and pocket the extra $$. If you built it on a cheap receiver (homebrew, etc...) you might even demil it and sell the parts out which are also worth good money. Or sell the back end (UF stock and parts) and use the rest of the kit for the type build you need.

My opinion on the UF is that it is the classic AK, so you should have one. They are nice and short when folded, and when open, are sturdy for a folder. The downside is the stock is a little slower to deploy than a side folder (wire or skeleton) and the cheekweld when firing it is a little uncomfortable. I have one that I built up, and will prob build another....but I mostly shoot my full stock and Romy wire folder guns.

Good luck

Thanks for the information.