The two bikes that I ride most frequently have SPD-R pedals fitted. I have two more bikes in the USA, one of which has old flat pedals, the other clips and straps.
Now that I'm used to clipless, I have to think when riding flat pedals otherwise I try to lift when climbing or accelerating...
Cheers,
Ed
__________________
Get a bicycle. You will certainly not regret it, if you live.