Range finders are a pain, and tend to be expensive if you want a curtain shutter and exchangeable lenses. And, despite our complaints about focusing with an SLR, I soon discover how much I use the ground glass when focusing - it takes a while to get used to the wee focus spot. There are some advantages, with either the later Japanese models or even the Cosina Voigtlanders: the viewfinder does stay bright and is large. Whether or not the RF spot works for you has to do with are there contrasty lines available to help you see. Fixed lens Yashicas, Minoltas, Konicas etc are plentiful and cheap, so trying one out doesn't mean a huge commitment.
As you mentioned RF and there hadn't been a comment as yet
I have written about this before, the KX viewfinder may be smaller and dimmer than the one in the MX, but that does not automatically make the MX better. What I appreciate about focusing with the KX is how well the image snaps into focus on the ground glass...
Eye Viagra comes in large sizes, and makes you slower. A 2x3 Graflex SLR with a 6x6, 6x7 or 6x9 back gives you a huge area of glass to focus with. The main issue is I wonder howcome nobody thought of preset lenses with these large SLRs or the LF view cameras. That's the main pain. And of course Pentax made some wonderful 120 cameras, which certainly make things larger to the aging eye.
(ps. I should mention that Gralfex made a doo-hickey for their RF where it shone a light through the range finder... two beams, where they crossed is where the focus was. This enabled anyone to shoot a black cat in a coal bin; but made sense shooting a sun flower in full sun)