Looking at going this route on the next boat. Looking for real world experience and opinions on both. $150k max. 496 or 500efi boats.

my first thought would be is'nt a formula much wider ?

I have spent a lot of time on both. The fountain will be faster with the same power. The formula is roomier, much bigger cabin. It has a full size fridge and the aft cabin sleeping is very nice, in fact its usually the captain's quarters for most ppl. The aft cabin in the fountain is small, usable for kids mostly. The earlier fountain 38s had a closed off front cabin which people either like or hate depending if you need privacy (in 2007 model year it was all open). If need the room and full size fridge, formula. If you want speed, fountain.

I really like different features about each boat.

I believe that Fountain used wood stringers up to a certain year (I don't know what that was). I have heard of many of them that needed repair or replacement. The Formula SS line uses some kind of a glass grid stringer system that won't rot. We really like our 37SS.

I shopped these for nearly a year......and just bought one 2 weeks ago.

We started looking for a 370SS or a 38EC. Even the 370ss is bigger than the 38EC. Then we got hung up on a 400ss....first I wanted blue motors, then I wanted diesel. It will cost more up front, but that is what you want! Why.......you'll soon notice most gas models are advertised with new drives or 2-3 year old drives and there is a reason for that!!! I also got test run data from Formula. Gas models get 0.9 mpg at best cruise. Diesel models tested at 1.65 mpg at a slightly slower best cruise.

We just got back a couple hours ago from a 3 day, 140-150 mile trip on a 09 diesel 400SS. A buddy with a Donzi 33ZX ran the whole way with us and I had a better fuel burn rate than he did! Plus, diesel is 30 to 70 cents a gallon cheaper on the water. (I spent $300 to cover 150 miles running heavy with gear/water, etc at a elevated cruise speed of 3,000 rpms @ 37mph)

Friends blue motors in his 40ss is 0.7 mpg real world. He was kind of shocked when he ran it out of gas ~10 miles offshore. Beautiful boat though. If available diesels would be the way to go.

Yeah, real world 1.65 in a diesel isn't going to happen either.......however I've already seen 1.4X at a slower cruise and did run back today doing 33knts (37.5 mph) at 1.29 mpg and had a crap ton of stuff we were bringing along with us.