...Also, unless it is noted above and I missed it, how many gallons of water do these water ballast boats carry as ballast? .
The Mac S and D models have 150 gallons for about 1200 lb.. The newer X and M I believe have about the same and I think the M has an additional 300 lbs. of lead in the bottom but not positive. Non in the swing centerboards or dagger boards, but some guys have added there.
Rule wise if you are racing and being honest some things are not allowed, but one guy recently bought a D and found out that the previous owner had put a couple hundred pounds of cement in the ballast tank, maybe for an advantage. And then there is the other advantage of dumping ballast while sailing. MacGregor corporation does not want you sailing with no ballast, but I've heard of some guys blowing it out when running in light winds. You should always have ballast in the S or D and in the X or M when sailing, but the X and M do dump the ballast if they are motoring fast and that is as per the company instructions.
Here is a good video about the S.....
...and would apply to the D and Part I for the X/M....
The Hunter water ballast boats are really nice boats and should be considered. More expensive new and used but kind of like moving from a Chevy to a Buick. The Chevy is fine, nothing wrong with it, but if you want a little more fit and finish the Buick is an option possibly if you have the money. They along with the X and M are heavier boats on the trailer vs. the S and D. The Hunter water ballast that wasn't a powersailer is no longer produced. They now have the Edge that is similar to the X and M. Like the Macs make sure you realize which type you are comparing with other boats.
The advertised weight of the S and D are about 1800 lbs. bare and with the trailer about 2800, but our boat loaded to go on the modified 2 axle trailer is probably 3600-3800 total and I'll bet most S and D's on the trailer loaded more normal with the outboard in the tow vehicle are a little over 3000 lbs.
I think the X, M and Hunter all start with a combined boat/trailer weight of 3500-3800 lbs before gear. We pull with a Suburban ourselves and with the heavier boats you might also consider that you need a larger tow vehicle if you don't already have one.
Happy boat hunting and here is a nice site to compare boats side by side,
Sail Calculator Pro v3.53 - 2500+ boats
Our 37 Endeavour --- Our 26 MacGregor --- Trips With Both