My humble few cents after 25 years with V501 …
In that particular order …
Pro’s
Resale value. Selling is easy even now.
I sold three times when I was short in funds and rebought again in more sunny days. Huge market for lens & accesories.
It fits in your palm. Perfectly. Kind of transition of your body. Try it with Rollei66.
Format. What others claim as nonsense, square is magic. Supposedly engineered for convenience - just crop vertical or horizontal for glossy journal pages. Composing sqare is Zen. Tricky but highly regarding.
Reliability. Good specimen won’t fail you.
I was confident as hell in every assignment .
Compatibility. Fully usable optics on digital - FF or MF.
Zeiss optics. No comments required.
Central shutter. All the goodness with flash.
Travelling. Good companion even with 1 lens of your choice.
Con’s
Age. Repair might be costly.
I do not recall which celebrity photog said that it is hard task to make a tack sharp image with hassy. It takes some practice. Almost all shots I made are with tripod.
Bokeh. Five aperture leafs, it’s up to your taste, background might be fuzzy wide open.
Format. Hey, it’s tiny 56x56mm!
Lens sharpness. It started bothering me after these years as I longing for high resolution in lower contrast. Mamiya Press is my fave now.
And last one - it’s emotionally hard to sell. My precious.