I have been going through the same thing, and here is what I have found.
You really have about three or four options.
1. Just have some type of bumper system and leave it at that. I just installed two 4' long 2x4's on my dock, and installed a fabric covered cushion on each. They extend down to 3" below water level, to 2' above the dock (at least). These are far superior to bumpers, but not good enough for leaving it for an extended period of time.
2. Stowaway. I have not used it, but I would not buy it simply because you have a hard object against your boat and dock. No way! It shouldn't be a problem, but I could see it being an issue really easy!
3. Other mooring devises such as this www.safeharbormarine.com
. I really like this system, but its the same price as whips.
4. Mooring whips. They seem to be ideal, safe. My biggest problem with them is looks. The people on this board that use them did not have anything bad to say about them.
At the end of the day I chose to raise my canopy on my lift up so I can just drive into my lift...with boards on my rack and all. If I am only getting out for a few seconds to pick something up...I just use the padded boards I noted above on the front of my dock. I figured that I wouldn't use the whips for something like that anyway. I have a single rope that is tied to the board next to me (driver) that is the perfect length to reach my pylon. I just grab it....slip it over my pylon, and get out. It holds me against the dock perfectly but not so tight as to screw something up.
Let me know what else you come up with, I am always interested. To me the ideal thing would be a 12" diameter tube that you inflate up against the side of the dock that could be permanent. That would be ideal....but I have not found it yet. You would think that somebody would have made a simple inflatable bumper in 10' sections by now....go figure.