I have bought mhx. Now I use a cia but its still nice to have the cartridge and the box
and Generations will be bought too so I can play with ma friends. I would just wait though especially if you have friends to enjoy the game together. Playing it in a party and learning all the new stuff is way more fun than soloing everything.
Btw to make mh love you, you need to get comfortable with it first and then start playing it. Push some buttons and continue getting better at timing and precision when pushing them. It will reward you with many rare materials. ( that you won't need that often in Generations)