Though the cement bench is by no means soft, of course, it's fine to sit on for half-an-hour or even an hour, and it's perfectly smooth, so no weird indentations! I sit on the bench, and lean against the wall, and the tree provides a little shade so I can read without being blinded by the white pages of my book. This arrangement allows me to enjoy my favorite aspect of cement: the way it absorbs heat. After a few hours of sun, the cement wall is deliciously warm, just the thing to take the chill off our perpetually chilly San Francisco days. It's the closest I can get to basking on a warm sun-baked rock, at least on my lunch break.
By far, however, the most luxurious piece of cement furniture I've ever experienced was the elegant lounge at Flora Grubb Gardens. On my annual fire-escape-garden plant-buying trip, I realized I'd bought far too many plants and bags of potting soil to tote home on the train, and decided to call a cab. It took over an hour to arrive, but the staff was so kind to me while I waited, and that lounge was so, so comfortable.
Does cement or concrete furniture hold any appeal for you? Outdoors only? Do you have really strong friends that would help you move it?