and if you are in the summer, the piper may be equipped with air conditioning.
Richard,
The OP lives in Ireland, so I don't think "summer" is an issue. He is probably more concerned about whether the door seals let the rain in.
My preference would be a Cessna. No groveling under the wing during pre-flight, two doors, a better sight-seeing experience for passengers and I've always found them easier to fly than Pipers.