Yes they are unwealdly and too heavy!  I can just lift and move a full hive body, if I move carefully!  I have dropped them a couple times, and the results, while not nice, have been far from disastrous!
If It's taking 30 minutes to move 4-5 frames into a spare box, you are moving a bit too slowly.  I'ts a trade off, it is, between moving slowly and not jarring the bees, and getting things done and the hive closed up again.  I think you can safely "Shake em up" a bit more,  in the interest of getting it done!  Just be sure you are using appropriate amounts of smoke.  Moving smoothly and quickly is an art that takes some practise to learn, but will come with time and confidence.  Do work the bees in the middle of the day(if possible), when as many bees as possible are out in the field.  It is a LOT less stressfull with all those extra bodies away.
I have found that the bees don't mind a bit of Jarring around- I just try to keep the banging to the minimun needed to get the job done.  I also invested in a pair of Frame grips.  These are handle like pliers that allow yoou to grab a frame by the top bar and wrench it free of the propolis binding it to it's neighbors.  This is so much easer and quicker than pounding and prying with a hive tool, and if done carefully, doesn't stir up or squish many bees at all.  Once the first frame or two is pried free with the aid of a hive tool, the other frames can be pulled free and moved in less than 5 minutes.
I prefer the frame grip sold by the Walter Kelley company  It is cast aluminum, with wide (1 inch) gripping pads, and provides a more secure grip than those with narrow gripping points.
I have used medium depth supers as bodies.  The bees like them fine, and they are sure easier to lift.  Three of them are usually substituted for two hive bodies.  The big drawback (Besides the extra cost, and time building more frames and boxes.) is when you go to find the queen, you have 1/3 more frames to look at in order to find her!  It takes a lot longer to inspect a three box brood nest than a two box one.   I can usually find the queen within 10-15 minutes in a two box setup- it takes considerably longer in mediums.  The queen seems quite adept at hiding among the extra frames, and more willing to run down below when you start inspecting the upper boxes.
If the weight is you problem, definately give the mediums a try- but be prepared to to spend more time when you inspect.
Are you dong this for the fun of it?  If so, consider a top bar hive, or a long hive.  No supers have to be lifted at all- you only move one frame at a time.  This set up is ideal for people with back problems, or those restricted to a wheelchair.  I don't get nearly as much honey from my TBH, but it is a lot easier to inspect than my langstroths.
Ellen, in Michigan

  Debra Sharpe <[log in to unmask]> wrote: ... but it occurs to me that the design of these
boxes and their unwieldy nature is a back injury waiting to happen (as I'm
sure all of you know) because it is very unlikely any beekeeper would drop a
hive body under any circumstances even if a back strain occurs.