I'm a little confused the heading shows Cat 28 MKII, but in your profile it lists Hunter 33 and your photo is a fractional rig which leads me to believe it is not a C-28. Anyway most of what I say will apply either way.
Everyone has an opinion and some will disagree with me. First I have a C28 MKI Tall Rig. I have owned it for 20 years. I have a reef-able main from the cockpit, I have an assortment of Spinnakers and a 135% on my roller furler. Most will tell you that the C-28 is not a racing boat and it is not, but they also back them selves into a corner with a 155%. A 135% will out point a 155% and a 110% will outpoint a 135%. So if your trying to race a 135 or a155 in mid to strong winds your giving up the world, you are using a sail out of it's performance range. For this use a 110% and back it up with a proper assortment of spinnakers and you will be competitive. Everyone else will out point you and leave you setting with a 155%. If I were to have only one Genoa it would be the 135% unless racing then a 110% The C-28 is also very sensitive to jib car adjustment and if is not right nothing will be.
A mast head rig gets most of it's power from the head sail and the main adds some additional power and balances the helm. On a fractional rig the main provides most of the power and the jib increases the flow to the main like a turbocharger and brings balance into the helm. You also have to be sure that the slot is clean and fair so as to not disrupt the laminar flow.
Tally Ho kind of confirms this. jssailem also seems to agree and also makes the point towards spins as well as add that smaller sails are easier to handle and I agree as I am getting older.
You also state that you solo a lot and it's easier to do just the jib. This in my eye is a lazy and dangerous approach especially with an auto helm. If your solo and under headsail alone with auto helm, make sure you wear a good life jacket because if you fall over the boat will sail on with out you and you will never catch it, this is why a boat is designed with weather helm, if you fall over just using manual steering it will head up, cross over, cross back, you have a chance of catching it. I do a lot of solo as well. If you go over with friends can they come back and get you if you go over?
As for reefing the minute you start to reef the sail degrades in efficiency the more you reef the less efficient. The foam is used as a filler to take the belly out of the Genoa, which makes a fat roll at the head-stay and distorts laminar flow as well and even more.
Stu, I tried to get onto the thread back to the C-34 site but was unable, it would not go but there was interesting posts on the thread I could get to.
I would add one other thing, if you buy a 1?? % sail it will always be better than the old blown one, but then how do you know that you got the best sail for your needs unless you buy two or three. On a racing boat that I campaigned nationally I had 3 mains, 8 jibs/genoa's, all different. You can tell significant differences in tiny things, even with spins, cut, weight, shape all do make a difference.
A sail maker worth his weight will ask a lot of questions because most sailors don't really understand how things affect each others, that is why you get the, well I jut need a bigger sail, probably not so.
Something that jssailem said made me smile. I have several spins, one I bought on kind of a joke, it is oddly shaped but it is huge, it is huge and due to it's odd size it won't fit a real big boat and is a bit large for mine but it was really cheap, really light maybe a tad bit ugly and colorless. It seems probably more than double the size of the one in his photo which is beautifu by the way. But when I launch that bad boy, I can hear it a mile away! WOOOOOOOW! So I had to laugh! That's my thoughts with out writing a novel, hope you find some gem to help you in there.
