I would rather be out of the saddle while climbing along with finding it easier. I think it has to do with body position. I have been told that I lean forward to much and that I should bring my body back a little more which would then allow other body parts to help and I would be able to tranfer more power if I did. Well I do what works for me. On a steep hill climb I lean forward over the bars, (my head usually over my front wheel) and I rock the bike side to side pushing down as well as pulling up with my legs. Be sure to control your breathing and get yourself into a rythme. Once you get yourself into a rythme than you find yourself concentrating on that vs how much further you have to climb or how tired you are. I also like to go from sitting to seated back and forth switching because it allows a break for certain muscles. since I prefer to be out of the saddle I sit for a rest vs others like to be in the seated position while climbing so standing gives them a break and then they can sit back down and wrench at it again.
hope that helps