I have already played "MH3 Ultimate" for the 3ds. At that time I could not motivate permanently the game. "MH4 Ultimate" has, however, a well-functioning multiplayer and much more "content" than its predecessor. I am totally satisfied, also the beginning for newcomers is much more grateful than its predecessors. Although tutorials are still only text boxes that you have to read but there are degrees of the important choice of his personal weapon, short missions in which you can try out the weapons in an arena. The new weapons have been added in MH4 all have their raison d'etre and no bad aftertaste just being an accessory. I am writing my review after almost 40 hours of playing time, and am yet still highly motivated though I (estimated) have played only 10%.
I have just a strong buy recommendation for new hunters.
Note: I play the game on the 3DS XL with the circle pit pro. The circle pit pro is not necessarily required, but who wants to have an extra camera stick, the circle pit should not forget to order. However, it's only matter of habit. A buddy plays the game on the old 3DS without circle pit and is absolutely thrilled.
For new hunter I recommend the tutorial from MH3 Ultimate on the rocket beans (.) TV channel of YouTube. Almost everything is explained and one is equipped for MH4 Ultimate!