Dropping the 1/3 stop aperture readout was a big boo-boo.

Modern SLR's let you set the shutter speed in 1/3's of a stop (ie 1/80 ...). But there is no need for a separate meter with a modern SLR although I'm sure there are a few who will clip it to their F6.

Outside of that the design is rather brilliant. I was skeptical of the optic-less aiming system for the spot meter but I built a mock-up of it and it works really well.

A spot meter only makes sense, to my mind, for Zone System work. If I am lugging a 4x5 or 8x10 along with tripod and all the other paraphernalia a Pentax meter doesn't add anything to my burden. So a super small meter is more a problem (where is that darned thing...) than a help.

Thinking about it a bit more, the meter would be a help to me if clipped to my Speed Graphic, where I go out for some hand-led LF work with a pocket full of film holders.

I would like to find a good meter for clipping to a meterless Leica et al. or a MF folder. I don't really need spot metering in this situation - what I would like is a clip-on matrix meter. You can't do ZS stuff with 35mm or MF as you can't develop each frame individually, and in any case with modern films and VC paper there isn't much need to. What you do need is to be able to place the important parts of the scene in the linear part of the film's HD curve - which is what matrix metering tries to accomplish for you.

Metering with a cell phone and appropriate app would work for an external matrix meter, but a clip on meter on my Nettar would be much more convenient. Especially if combined with a rangefinder.

For the authentic Nettar experience I set the exposure by a sunny-16 exposure table. The one my Mother had taped inside the case of her Nettar has blown away - but as it was for Kodacolor-II it didn't have much use any more, only sentimental value.