I had a beater MTB bike a few years ago. I rode on the trail in the pouring rain. 40 miles of soaking wet fun! I'd probably do it more often but I don't have the bike anymore and I don't like getting my roadies full of grit etc.
It was fun though. I had to stop at a park and ring out my entire outfit I was so saturated.
It was exhilarating and one big 40 mile rooster tail. I took my camera double wrapped in a baggie but no other electronics.