They're really coming out of the woodwork. Don't think I've ever seen a Discovery Plus before, but I'm pretty sure that those little metal bars on the bottom of the brush rolls changed to plastic around 1989-90ish, when the Regency Series cylinders came out and the power nozzles were updated. This was also about the time they did away with the stationary brush strip on the bottom of the power nozzle.
I'm more or less half and half on the collecting/using business. I do like to collect various models, and would ideally love to have all of the Aerus/Electrolux uprights and cylinders, but I also insist that they be usable and used. I don't want anything just sitting there looking pretty (even though they do look pretty). If this machine is something you think you might get some use out of, I'd go for it.
Re: the differences between the various models. I only own three uprights: a Discovery III, and two battleship gray Epic 3500s, so I'm not entirely the best person to ask. There must be a few on here who have a greater variety. That said, I don't mind sharing my impressions, bearing in mind that I'm using these machines more or less as they came to me, in used condition. The only maintenance I've done on them (other than exterior cosmetic cleaning and disinfecting) is to wash the brush rolls, and clean the dust and dirt out of the fill tube and power nozzle motor and casing.
- The cleaning performance and suction of the DIII and 3500 seem more or less equal...maybe a slight edge to the 3500. The 3500 seems noticeably easier to push, and glides more easily over the carpet.
- The 3500 is easier to carry, with the carrying handle. You have to grab the DIII around the metal post, and, because the cord runs up the post, you have to be sort of careful not to put a strain on it when you're lifting it.
- As you said above, the 3500 has the connection for the electric hose, which puts it pretty far ahead of the DIII in that you can use the Sidekick. The plastic hose on the DIII is adequate, but it doesn't swivel at the handle end and it can be pretty stiff in certain situations.
- I find the rocker switch much easier to use than the slider. Many times with the DIII I end up turning the whole thing off when I merely want to turn the power nozzle off.
- I know its not necessary, but the headlight on the later models is sometimes a useful function to have.
Didn't really intend to go on this long, but I've really fallen in love with these uprights. They're so easy to use, and, given the condition mine arrived in, can take a hell of a lot of abuse and keep going. One of my 3500s was absolutely gunked up, right up into the fill tube, with dirt, hair, and God knows what else, and it still ran and had plenty of power (of course, I cleaned it out).
Comes to the Rescue!
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