Tall speed, Std. height
The following comments are not C30 specific. My experience has been primarily with a C25 and C310.I find it almost impossible to answer a question about tall vs standard rig speed without knowing the typical wind speeds the boat will be used in. Where there is frequently enough wind to move a boat at hull speed, then there is no real advantage to a tall rig at all, and carrying extra mast weight and windage may actually be a disadvantage. But as the wind gets lighter, the tall rig’s advantage in speed increases. PHRF usually indicates a difference of maybe 8 seconds per mile, but that’s for an average wind speed, and it varies from area to area. In my experience, the tall rig may be a tenth of a knot or two faster at best. I sail in Puget Sound where the wind is usually 15 knots or less (sometimes much less), but I have also been beaten by standard rig boats on occasion. In this region I only need to reef a couple of times a year. I personally would always prefer a tall rig option for this part of the country.Even though I do some casual racing, I think of it more as a test of my, and my boat’s sailing efficiency. It helps to improve my sailing skills, and keep me sharp. Even when not racing, I enjoy sailing as efficiently as possible. On the other hand, I know some people who just enjoy being out on the water. My point is that except in high wind locations, and issues of bridge clearances, I see no disadvantages to a tall rig, and some possible advantages.Also, be careful about height above waterline if you're trying to cut it close. It can vary, based on how fully loaded a particular boat is for one thing.