The best answer might depend on What problems you currently have with your feet! I've had bunions, hammertoes, plantar fasciitis,a neuroma and gout over the past six years. When I had the neuroma I couldn't bike for more than about 15 minutes because of the pain: ALL the pressure goes through the ball of your foot. However, biking was better for the bunion, hammertoes and plantar fasciitis than walking....
I would seriously suggest you take this conversation into your Podiatrists office and get their advice for your specific issues.
and All the Best--you certainly have my sympathy!! patti
PS--There is Hope--following several foot surgeries, I can now walk 5 miles, and bike 2 hours. My feet will never be "normal" but they are certainly functional with much less pain!!
Patti "The only thing we have to decide is what to do with the time that is given to us." Gandalf: Lord of the Rings