Random meter thoughts:
I have the Digisix and don't consider it fragile. Yes, it's made of lightweight plastic -- but that means that if you drop it, it doesn't hit as hard. My main beef with it is that the readout and dial are hard to read in low light.
Speaking of cheaply constructed, I looked hard at those Calcu-light units when they were new, but wound up walking away. The electronics may have been first-rate (although back in the day they did have a reputation as battery-eaters) but the cases, hardware and general construction struck me as excessively cheesy. They may be great meters for all I know, but I would suggest NOT buying one sight unseen!
If you like the Westons but need higher sensitivity, you might want to try to find the Ranger 9 CdS (model 348 -- made, incidentally, in Newark, N.J.) It has the same well-liked calculator dial and general shape as the Master models, but is hugely more sensitive thanks to the CdS cell -- it reads at ISO 100 down to EV -2.5, which corresponds to an exposure of 5 minutes at f/8 (!) It even has a rather accurate little bright-line viewfinder built into it, to help you aim its sensitivity area at the subject.
I had semi-retired my Ranger 9 because my stash of PX-14 mercury batteries was dwindling -- but I just found
this page about converting it to use silver-oxide cells, so that's my new winter project!