The PeeKay 3500 A and B floats (straight and amphib versions of the same barrels) are incredibly stout, well built floats. They handle rough water better than any other float I've ever flown. They also offer a lot of floatation.
I've flown one or the other version of these floats on 185s, 206s and a bit on a Murphy Moose.
The problem with these floats is that they reach a "hull speed" beyond which they don't want to accelerate, at a speed below the stall speed of the airplane. Getting them to accelerate on the step beyond that speed takes lots of thrust and patience. Also, the "sweet spot" on these floats is extremely narrow, which is typical of many PeeKay floats, but worse in these. A pilot who is proficient with these can make them work, no doubt. There was an air taxi in Kodiak who used them on 206s and they did fine. But you have to be right on your game, and in glassy water.....
These floats were developed by PeeKay Devore (a major provider of military aerospace gear) based in New Mexico.......think about that.
Unfortunately, these floats gave PeeKay floats a bad name when it comes to performance.....not all of which was the float's fault, or a deserved rep.
They fixed the performance with the later C and D model 3500 floats, but the rep still hangs over PK floats. Later floats are great. These are good strong floats, and they'll take incredible abuse.
Good floats, but they'll make you work at flying them.
By the way, that Moose did pretty well on them.....lower stall speed.
MTV