Welcome to the site !!
I guess it depends on what specific uses you will want for the bike , if its mainly on the road and little if any off road , then I would suggest a 250L rather than a X , as it is specifically built for the street and light off roading/fire roads , if you were 70% off road and some street , then the X would be fine and a better choice for that purpose , The X you would basically want (if you did any serious off roading) 2 sets of tires , 1 for dirt and 1 set for street , or at least DOT approved knobbies/trials tires , with the L , you have street legal tires you could also use off road though not as diligently as off road specific tires , ...... basically , the X is a off road bike you "can" adapt for street use , the L is a street specific bike that you can take off road , though not to the extent of the X without damaging some of the components , like turn signals , tank , muffler , etc.
Hope that answered your question