The Hi-Soft cutting board from Korin ($69.90 for the 15.75"x11.5"x0.78" board) is made from polyvinyl acetate, which is about the same hardness as wood - just about right for your knives. In using the board, I thought it might have been just a tad softer than my favorite old wooden board, but I could be wrong. Maybe it's just that, unlike wood, there's no grain in the material.
The benefit to this type of board over wood is that it can be soaked water and washed with whatever soap you like or cleaned with bleach - since it's not porous, it won't absorb the soap and it won't warp, crack or split. However, this board can't be washed in the dishwasher or exposed to very hot water - too much heat could soften it or make it warp. So, hand-washing it is. Not a big problem for me since this wouldn't fit in my dishwasher, anyway.
I have to say this board is a nice size - big enough to be useful, but small enough to be easy to store (and you can order larger sizes as well). The color isn't quite as pretty as a wooden board, but it's not shockingly ugly, either. One of the things like I most is what the board doesn't have - there aren't any feet, so the board can be used on both sides, and there are no handles or grooves, so the whole surface of the board is flat and usable.
This cutting board isn't so outstanding that I'd suggest you throw out the ones you own, but if you're looking for a new board this one is a good choice.