I love this type of cleaner, but I also think it has some serious shortcomings.
What's to like? Well, mainly the fact that it was completely different from any other upright when it was launched. The use of plastics for the bulk of the cleaner was very unusual too, as I don't think plastic canister cleaners hit the market til the early 1970s (in the UK anyway). It's beautiful too, with that tapered body - anyone know if this machine was a Henry Dreyfuss design?
On the other hand, handle wobble was never sorted out, the plastics are rather fragile, dust falls from the tool port sometimes, I don't trust the offset carpet suction duct to clean properly (especially the oppposite edge), and they're so heavy! The Powerdrive versions are particularly bad - light as a feather to push, but try carrying it anywhere...
One thing I have recently noted with my machines is to never use them on full carpet suction unless totally necessary - otherwise they cling to the carpet, and are very hard to push.
But you can't knock the machine too much - it's unreasonable to expect such a step into uncharted waters to be perfect. And of course it is the grandaddy of just about every new upright cleaner on the market.
By the way Ian, yours is Mandarin Blue, same as mine. I wonder if yours (and mine!) had the main casing replaced at some point - I see yours has a blanked off bit for a switch on the main body, like the later U5002 had. I thought mine might have been a crossover machine (built November 1974), but the fact yours also has it (but Seamus' 1973 model doesn't) is intriguing.
I never understood why (In the UK at least) this machine had no headlamp (apart from the Power Drive and the late model U5032) when it was TOL. Or why it seems to have been particularly popular in Italy...