Same situation
Rick, I've an 2004 306 that I took delivery of just a few months back and am under the same impression about the main thus far. I have only had a couple days of decent wind (12-15knts +) when I was at the boat to begin to tune the rig. I have adjusted with various combinations (rake, bend, tension) looking for the 'sweet spot' but need decent wind which is rare in my area this time of year. My initial impression is that sailing with the main alone on this pudgy, top heavy little gal is going to be more relaxing than exciting. I have used my vang adjustment to trim with success and can trim out the flutter you refer to with the various controls available on the boat. You are dead on in that she really likes the jib. Every boat is different but I've been logging my adjustments with a Loos gauge/tape and will share when I get it as close as I can if you are interested. By the way..If you haven't checked your Sea-Fire system do so. I missed a few good hours of wind this past Sun. not really understanding how the system works and why I couldn't start my engine(I've never had one and failed to learn its operation/shame on me) Anyway Sea-Fire has a problem with a few systems on 306's most of which were mfg the latter part of 2003 as I understand it. Have a great day!