The thing about the 3-speed frames is that often they have a relaxed frame geometry. With upright seating, this makes for a more stately ride.
Since I do have hills to deal with, I installed a 22-tooth cog in the rear, so I have two gears for climbing. I don't find the bike to be particularly slow- I'm easily able to get it up to 25 mph and more, which is not bad considering the riding position. But although I have a number of bikes that are lighter and faster, I find that most of my riding is on this bike. It is well-suited for light errands due to its rack and fork lock (I don't seem to need to carry a separate lock with this bike as a result).
From what I have seen of the Raleighs, the Sport and the Superbe are the best bets if the bike was made in the 1970s or later. Not to say that I have not discovered a few fit and finish problems with my Superbe, the worst being a poor casting on one crank arm that caused it to engage the BB hardware. A bit of filing sorted that out. A lot of filing actually. I do find though that I prefer the ride of my Humber Sports even more. Can't lock the fork though...
The Superbe gets complements all the time. Its funny, I have to take one of my high-end rides into a bike shop before it will get complemented by people I don't know, but on the street the Superbe does it hands down over all my other bikes put together. Actually its gotten complemented in bike shops too. Still can't figure out why a good British three-speed can be so charming, but cares?? Its fun.