Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling - Pedal recomendations?

I am trying clipless pedals for the first time and want to get a set that will cover many uses (casual riding, commuting, & long distance riding). For longer distances (100+ miles), are larger platform clipless options preferred for comfort? I'm looking at the larger platforms because it would allow me to ride with regular shoes for short trips (exercising the dog, etc.) but am wondering if they may be problematic as I work toward century + distances. I'm looking at Time ATAC Control Z pedals and similar options. Thanks, I look forward to your advice.

Take a look at Crank Brothers cuz you can use a recessed cleat on all of their pedals. Also, models such as the Acid and Candy can be used quite well with shoes.

For longer distances (100+ miles), are larger platform clipless options preferred for comfort?

If you have stiff soles in your cycling shoes (most do) and the shoes fit properly, a larger platform is not essential. I use Bebop pedals (smallish platform) with no problems.

I prefer larger platforms and get hotspots with smaller ones. Stiff shoes help, but can be annoying when walking around at rest stops, etc.

I ended up liking Shimano's A520 Touring pedal (http://www.biowheels.com/pdsha520.html). This has a nice large platform, and the cleats are recessed so you won't mar the wooden floors at the sag stop.

Thanks for the comments so far. I want to hop on the bike for a quick spin (exercising the dog = 1-2 miles) w/o using the shoes because the dog like to make sudden stops.

It sounds like the consensus is that the shoes dictate comfort for long distance riding (vs the pedals)? This is assuming of course that the amount of float is adequate (rider fit)?

In my experience, very stiff soles make almost any pedal comfortable. Anything less than "very stiff" places more demand on the pedals. So thick carbon soles allow you to use any pedal you like, but will make walking unpleasant. More "walkable" shoes are very useful to the typical LD rider, but then you'll want to look into pedals with bigger platforms.

I am thinking about these but they are a little pricey. Their weight isn't too bad. The "D" is larger than the other. I think you could wear a pair of Chucks with these. If they were not so pricey I would have bought them. I'll stick with my crank bros for now.
http://aebike.com/page.cfm?action=list&PageID=30&category=463&modelId=15762&type=T

Umm, these are not clipless? I have a very similar pedal on my bike right now (big, honking BMX style pedal). Not bad for short rides but I really noticed a lot of pressure on the ball of my feet after 200k (since that is what was pushing on the pedal). I'm hoping a clipless setup will remedy this problem (force of pedaling will be distributed across the entire footbed).

Umm, these are not clipless?

my bad, I really got to read better.

Thanks for everyone's tips. I went with a pair of Specialized BG Comp MTB shoes (last year's model, got 40% off) and a set of Time Roc S pedals. I played around with a variety of pedals on my bike and decided to not go with a compromise solution (clipless and street shoe riding). I liked the steel loops on the Roc pedals (vs the aluminum on Time's more expensive MTB pedals), the larger platform, and the fact that I won't come unclipped if the bottom of the pedal hits anything. This will allow me to use the same pedals on a MTB when I go down that road. When I need to walk the dog (once a week) I'll hop on my wife's bike or just swap out the pedals (to my BMX platforms). I have 30 days to try them out, hopefully I'll enjoy the clipless experience. Thanks again for all the suggestions.