Originally posted by Apple:

is this game just as good on single player . or better with people

Preferably with one or two others max. Although, if you are a hardcore gamer and they are casuals, it will annoy you, but you will have to adjust. You may end up carrying them in fights, dodging and moving around like a pro while they struggle with 1 mob and you have to handle 5-6 + an elite or two, buuuut, farm-wise, it's much more efficient.
Well, if you are at about the same level as your mates, then yeah definitely 2-3 people.
Edit: Plus the base-building is more fun too