Until you take off from a hot, dry prairie runway and land in a secluded, cool, high altitude lake, then you really have not had a taste of what aviation can really do.
The Seawind did not have the tail feathers far enough aft but it did offer a 200 MPH air speed ability to cover the miles.
Pontoon AC are horrid machines that need 14 to 16 foot tall hangar doors.
The Lake 250 was a very refined hauler with great water and flight handling and it was 1000 lbs lighter than the Sea Wind, but the bulky sponsons provided about 20 kts of drag
Flying Boat lake amphibians fit in normal hangars and are aerodynamically CLEAN as soon as they are off the water.
I think a Lake 250 type hull with RV-10 wings would provide 4 seats plus baggage
or 2 seats plus lots of camping gear and baggage ability.
A home built Lake 250 Amphibian that flies at 200 kts but lands at 52 kts would get me on the VANS customer list faster than anything else.