I have a 1972 Raleigh sports. It is a secondary commuter. I stay above 15 mph average on my 6 mile each way commute with a number of fairly short hills. I also have a Novara Fusion and a steel road bike built up from a Fuji Marseille 2003 frame. The Fusion isn't any faster in most circumstances and the road bike is only a little faster; just a minute or two probably in six miles. I'm not really a fast rider or in that great of shape, but I pass full kit roadies on my Raleigh Sports on the MUP regularly. In that picture of the Sprite, the seat is really low. I wonder if the seller had it too low or was too small for the bike. With a Sprite or Sports the seat (Brooks B72 perhaps) should be about level with the middle front of the bars I think. Maybe it's just the perspective on the photo and the fact that it isn't the diamond frames I'm used to.