Can Cable Really Be Slower Than 56K?

Ralph Bearpark asks: "June's IEEE Software mag carries an article titled 'The Cable Modem Traffic Jam' that claims (amongst other things) that 'a 56K dial-up modem can at times be faster than a cable modem and access can be more reliable' due to neighborhood bandwidth hogs, billing system bottlenecks server overloads, and various other problems, many of which apparently also apply to xDSL."

"Now, I had been seriously considering upgrading to cable, but now I'm not so sure whether it will be worth the extra cash. What is your experience? Is broadband really slowing down?"

I'm working at a cable-modem connected computer which really does seem sometimes to lag behind good old 56K -- anyone out there have advice on avoiding The Great Slowdown?