Agree with Steve-
On my H25, I have a 135 and a 110 (both hank-on sails), and they work quite well. I've only RARELY wished for a 150, and that was on days when the wind was only blowing 5 knots. The 135 is about all I'm comfortable with in any kind of moderate wind. On a boat with roller furling, it can be rolled down to about 115% without losing too much performance. A 150 is a little big for the boat, I think, unless you're running off the wind (in which case you'd want a spinnaker anyway). A 150 can be rolled down to about 130% before the performance drop is too great.--Jon BastienH25 'Adagio'