The boat dock is at Yacht Club, if that matters. I have a knee problem too and found it super easy to stay at YC and get on the boat to Epcot or DHS. It saved a lot of steps, not walking to/from Epcot, and not walking from Beach Club to and from the boat dock. We didn't use the Marketplace at Beach Club, though... if we did, that would have been a ton of walking.
That's another reason why we are thinking YC, although DH still wants to do the walking path to Epcot since he says the boat takes too long. If I do have a scooter, we'll likely still do the walking path from BC and boat to DHS. I'm not sure how much we'd be using the Marketplace either as we are planning to stay CL and will have the lounge for breakfast/snackies.
Please listen to your DH and rent a scooter. If a few extra steps to the boat will make that much of a difference then how do you figure you can handle walking around a park? Do yourself and your DH a huge favour and get the scooter. You won't regret it. Not getting it on the other hand is something you likely will regret. If your knee gets really sore then you could end up laid up for a day or two. Does that sound like a fun vacation for you or your DH?
Get the scooter. You won't regret it.
Oh, and to answer your question, I think YC sounds more your style. Don't choose based on those few saved steps to Epcot. You'll have a scooter anyway, right? Choose the resort that feels more suited to your tastes.
I can walk for one or two days at the parks without a lot of issues, but I am worried about the five day stay. He originally didn't want me to get a scooter, but now I think he's changed his mind again. I think I would need one for the reasons you listed. I just hate having to drive one of those things at the parks. People cut in front of you in lines, kids dart in front of you, you get a ton of dirty looks and rude comments, and I do a really rotten job driving those things. People were hateful the couple of times I took a bus (even though I wouldn't "skip ahead" people who had been waiting a long time and there were only two in our party) so we drove most of the time. I had to have one for our 2008 trip or my doctor wouldn't allow me to go, and it was just an all around unpleasant experience. Still, I was at least able to walk when I got home, and I did enjoy myself in the parks.
I have a question maybe someone here who has rented a scooter can answer.
Can you take the scooter on the water taxi to DHS?
TIA
Yes, you can and it's probably the easiest form of transport to load one on. They have a little ramp they put down and you just drive on. They gave me the option of sitting in my scooter on the boat or parking it and sitting on a bench. I always chose the bench because I didn't feel secure sitting on the scooter while the boat/monorail/bus, etc. was in motion.