Road spds are nicer I think but it’s marginal (I’ve got spds on my commuter and spd-sl on the proper road bike – I reckon the difference is 90% die to the lighter weight and stiffness of the road shoes – carbon soles etc.
Agree spd-sl is harder to clip in/out – it’s getting better with time though.
I trashed my first set of cleats in 3 months – walking maybe 100 meters a day in them when commuting. Bought some clear covers when buying replacement cleats and the problem has gone. As the walk is at the work end I might just leave them in the work bike shed rather than carry them.
If was buying again from scratch I’d find some very stiff light carbon sole SPD shoes to get the best of both worlds.
Edit – just like those linked to above. If they were in stock you would have seen some 105 SPD-SL pedals and Specialized road shoes in the classified next week!