Hey there. Nice to "see you" again. I have 2 now and another 2 waiting for DMG to be able to get back to work and ship. So you can see from that that I really like them. I tend to work on a "block" of minis at the same time so I can use up paint/wash on multiple minis at a given time, and don't get stopped because I have to wait for something to dry.
The shaft is 4.5" and the middle of the ridge near the bottom is about an inch higher off the bottom. I don't have a tape measure, but my ruler shows 1" across at the widest spot. If they had a female version that was about .5-.75" shorter, I would buy that instead, but I don't think the size is too big for my hands. I have relatively medium female sized hands. Definitely smaller than any of the guys in my gaming groups. I've got some arthritis starting to settle into my top knuckles, and for me, the the width around is perfect for me. I can paint all day, and my hands don't bug me at all. I usually have my pinkie riding in the ridge near the bottom, but sometimes I feel the need to move my hand higher and drape my index finger over the wire. I'd been used to using pill bottles, and this is an easier grip for me, but the biggest adjustment was remembering that you want to put the handle back on the base, and not just set it down on the table. I'm used to it now, but it took a while. Kind of like when I had lasik on my eyes, and was still reaching for my glasses in the morning for a while. Finding the base is nothing compared to how often I dumped over a pill bottle (even with change in it).
The minis I'm painting are not large, but I have no problem with the wire being in the way. You can spin the handle around. The top of the cork is the same size as my dungeons doggies (most of them) and cats in the catacombs minis. I have free access to the bottom parts of the mini (unless the mini would have no access regardless of what holder you used). I've painted about 5 minis on each handle, and the corks look as good as the day I got them. They arrived with an extra cork. I'm sure you would be able to get replacements if needed. (@konas said as much to me when I shared that concern with him when I tried it out as a beta) The biggest surprise is that I haven't slopped any paint on them yet. I can be kind of a spaz with the paint brush. I'm digging using the top part of the wire support when doing real detailed work on the top half of the mini. When I'm working on the bottom half, I do the drape over the bottom of the wire trick.
As far as weight, it's pretty light. I have a Mora one and a Redheart one. About the same weight as 2 empty pill bottles with lids, but lighter than 1 pill bottle full of change.
I haven't done any medal minis, but I've found the cork holds just as good or better than my pill bottle lids did with the blue or orange mounting stuff. Maybe someone else can speak to using them with metal minis. This bad boy is pretty big, and I had no problems with him.