We've used the Whale through the sole foot pump and a whale look alike lever action foot pump. The lever action foot pump pumps on both the up and down stroke so pushes more water, more quickly but takes up quite a bit more space. We used the ersatz lever pump because it could be mounted to the vertical face of the bulkhead. From what I saw of the Whale pump, it had to be mounted on a horizontal platform, something that's either not been possible or would require a bunch of work to create the platform. I can't remember the manufacture of the ersatz pump. Found it on Ebay at quite a bit less than the Whale pump. I didn't see that there was a rebuild
kit for the pump, which there is for the Whale so how it lasts only time will tell. So far it's doing a great job.
The through the sole pumps worked just fine for us in 4 years of live aboard and cruising. They utilize space that is otherwise wasted and don't requre as much care in using. Of course, you have to check and see that you have enough depth
under the sole for the install. You can stomp on these pumps to your hearts content and probably couldn't hurt them. The lever action pump seems a bit fragile as you can depress the pump lever beyond it's stop torquing the mount and/or possibly damaging the pump and lever. Think I'm going to mount a block of wood under the lever so it can't be depressed beyond it's designed range.
As others have stated, the advantage of a foot pump is they leave both hands free for more important things like hanging on when it's really rough or just washing
the dishes. The REALLY REALLY BIG ADVANTAGE of foot pumps is conservation of water. Pressure water systems are huge wasters of water. No matter how careful you are, most of the water that comes out of the spigot just goes down the drain without doing anything useful. With a foot pump, most of the water gets used for what's intended. In our case, we could go a month or more on a tank using only the foot pumps. When we used the pressure system, that same tank would run dry in a week. I'd seriously consider not having a pressure water system for potable water on the next boat. Money
would be way better spent on a salt water
pump for the anchor
chain and deck