efficiency; sound levels; old vac reconditioning?
Here's a question or two (or three

. How does one compare the electric power consumption of a vacuum to its suction power? And are there ratings or standard numbers of this type to be found for newer vacuums? The point being, all other things being equal, a more efficient machine is preferable to one that wastes electricity relative to work performed.
About reconditioning machines, and which are worthwhile:
Without even trying, I managed to accumulate four canister-type vacuums here (and I'm not even an appliance collector!). Understood that some of the folks here think that any vac made of plastic is inherently inferior, but my goal here is primarily practical rather than historic.
One is a Sears Kenmore, model number on the bottom is 116-4695, looks to be mid 1960s, light brown bottom half, white plastic hinged cover, with a bag full indicator light and, interestingly enough, a 2-speed motor switch on the back. I recall my family had one almost identical to this when I was a kid, but it had a retractible cord; it looks like the cord reel may have been installed inside the machine. Retractible cords are a useful feature; does anyone here know of a source for the internal cord-reel component so I could install it on this machine?
A couple of years ago I found a Hoover Tempo, model S-1323, sitting next to the neighbor's trash out front. No way in h*ll a potentially working machine should go to waste, so I put that in service. It seemed more powerful than the Kenmore, but it's so noisy as to make vacuuming an acoustically painful task.
A couple of months ago I was visiting a friend, whose housemate was cleaning out the garage. An old Electrolux was sitting on the trash pile. "You're not going to let that go to waste, are you?" "If you want it, you can have it." OK. Two days later I saw another one sitting next to a trash can and figured, "take two & make one," as we used to do with partially-damaged telephone equipment. I haven't even started trying to get either of these working yet; they are in pretty serious disrepair (are they worth having reconditioned, and if so, does anyone here do that kind of thing, and what's the price range?). These machines are in the garage and I can get the model numbers tomorrow; they appear to be 1960s to 1970s models, one is beige/brown, the other is dark blue.
So now that y'all have me thinking about vacuums, I've recalled something I read that the manufacturers' market research found that people "say" they want quiet vacuums but "actually" buy noisier ones on the basis of the assumption that noise means power. Suddenly it dawned on me that I might have been making the same silly mistake about the quieter Kenmore vs. the noisier Hoover!
Here's something I just thought of as a rough way to measure suction power: Get a piece of thick flat plastic of appropriate dimension that it could be "stuck" to the end of the suction pipe. Attach a hook to the center of the piece of plastic, and hang increasing weight on the hook (a bucket of water, keep adding water) whilst the flat plastic piece is stuck to the nozzle. When the weight finally pulls the plastic piece away from the suction pipe, that's the limit of the suction. Water has a constant ratio of weight to volume, so knowing the number of gallons of water would enable calculating the weight that finally caused the plastic piece to be pulled free of the suction pipe.
Where this is leading: Based on some of what y'all said about Kenmores being good machines, and my recall of the item about noise vs. suction, and the fact that my Kenmore has a 2-speed switch (lower power consumption in low speed mode, useful for certain tasks), I think I might just do a decent refurbishing job on that machine and put it back into service as my primary indoor vac. (Ha, unless someone here manages to convince me to buy some classic mid 20th century cleaner in a metal housing; one never knows!
