Linda - the Shimano pedals will have the same re-orientation issue, they generally hang wrong side up.

My +1 and I recently got Speedplay pedals to replace our Shimanos - his were Ultegra, mine were 105s. He got the zeros that you are considering while I got the easy entry ones and we love them. He's ordered a second set for his commuter bike because he didn't experience any knee pain from his first two rides with the new pedals.

The cleats are much bigger as ozrider said, but we also got 'cafe cleat covers' that are easy to carry and slip on and it's a breeze to walk in them. Even without the covers they are not harder to walk in than my Shimanos.

But the best thing is that you don't have to re-orient your pedal - the double sided entry is woth its weight in gold.

The only drawback is that you wouldn't be able to get a cheaper pedal for your winter bike - it would need to be the same one. And I think they are always sold with cleats - but then you'd have a spare pair of cleats.