I got 3U for Christmas and got about 21 hours in before I got caught back up in school again. I just picked it back up 2 days ago and have put in about 20 more hours! I've been using the Switch Axe the whole time, and I can tell you some great things about it:
1. It has two modes, Axe for heavy hitting and faster movement, and Sword for slicing and slower movement.
2. It makes you have to learn a monsters movements so you predict when it will attack and how. You will be dodging all the time.
3. It has some amazing range, being able to hit in front of you, on your sides, above you, and even slightly behind you! It can knock flying monsters out of the air, and is great for breaking different monsters heads easier.
The Switch Axe also has different abilities you need to use to your advantage. For the Axe, you will use X and directional inputs for most of your combos. Standing still and using X is how you hit above you, to hit heads and flying monsters. A and X when pressed at the same make you swing directly up. This is also helpful because after you swing directly up, you can continuously press A to swing it in a loop to get tons of hits, however this uses stamina.
The Sword can pretty much combo with A and X with ease. Pressing them together then pressing X continuously will stab the enemy and keep damages them until it explodes and puts you back in Axe mode.
Hope this helped!