Originally posted by Rhapsody:

IMO it's a waste of time to explore mountains until you've gained the loot from Bonemass.

After pondering I agree more with Rhapsody especially if it is your first play through. This game actually has great replay-ability in my opinion mainly to try different tactics (boss/biome order, weapon builds.....etc). My first play through I did everything exactly as the devs intended and had a great time. After you get more comfortable and want to switch it up, skipping bosses(armor sets) can be alot of fun on a future playthrough.