KDX or Yam ???Which one for me ?

Even though you didn't state your stats(hiegth/weight) both bikes are really good beginner bikes and it's meerly a choice of which kind of power you like. The WR may help more if you a complete beginner but since you've rode a bike before either will do. The KDX has more of a hit(than the WR) and more top end power. Test ride a WR and see how many strokes you like. Or if you already know from your past expirence make the conclusion and act. Personally I would grab that KDX now depending on the price and condition. The KDX has way more mods to make it suit your riding.

Height plays a big part in this. Personally I would go for the KDX its an awesome bike. The WR is supposed to be a beast to start but an otherwise good bike. I was thinking about a WR to but what held me back is the size....that thing is HUGE!!! I fit on the KDX way better. I think it is a good idea to take a WR for a test ride if you can just so you know how it suits you. Then you'd have a better idea of how each bike would be better for you.

go down to the local Yamaha dealer and sit on the wr and i'll bet you'll like the feel of the KDX better . so much more things you can do to the KDX for future mods , it is endless . either way you go both are good bikes .