It's pretty difficult to say that one hammock is more comfortable than others because everyone sleeps differently and has different preferences. I think that IN GENERAL... the mayan and brazilian tend to be the most comfortable that I have heard of and I can verify that my mayan is the most comfortable thing I own. If you live anywhere but the tropics then you might want to look at a brazilian hammock. I would just try the one that you ordered and go from there. It might be all that you need. You also may want to consider hanging it at a diagonal in the room (like others have mentioned) so that you can get a big mayan or brazilian (if that is what you go with) because with those types of hammocks bigger is better.
As far as sitting in a hammock... just fold the hammock over onto itself and it will give you a good platform to sit on (instead of being like sitting inside a canoe).