Sure, folding cutting boards can be handy, and certainly there's the ease of mind that comes knowing you can put your plastic cutting board in the dishwasher or bleach it - and I won't lie, I have both types of cutting boards.
Of course, those extra cutting boards only make a few appearances per year, and only in a supporting role for the main event: my heavy, tiled butcher-block cutting board. This is my daily cutting board and it gets a lot of abuse.
The board will not warp. The board can take heat. The surface is made of dense hardwood. Cleaning? I soap it up once a month on both sides and dry it in the oven at the lowest heat.
I use a clean dishtowel with warm water to wipe off miscellaneous detritus for daily use, and if meat was cut, perhaps I'll rub in a spoon full of Kosher salt.
The surface works great for kneading bread and pasta dough - I'll use a damp kitchen towel to hold the board in place.
New, these cutting boards are often very expensive*. Try to find one used, and they will retain their value, but it will save you some money over having to pay those thieves at Sur la Table (just kidding, we love Sur la Table).
* Retail price for a new 18"x18" will run you well over $120.