DIGITAL STYLUS GAUGE

They’re all good so long as the weigh pan is in the plane of the LP surface AND is not magnetic.

I checked the recommendation from Robert53 for the Ortofon stylus gauge.  It seems to fit the criteria of good build quality, accuracy and ease of use.  Notwithstanding that it is 3 times the cost of the Riverstone, the ease of use is very helpful and a little over $100 is not outrageous--like some of those that go into the hundreds of dollars.  My only concern is that it is made with aluminum.  Would that affect my MC cartridge?

I own an Ortofon DS3 (I think that is the alphanumeric designation), and the weigh pan is not magnetic, if that helps.  Pure alu is not magnetic, but best to check with a powerful magnet. Also, the important thing is the weigh pan.  The casing can be made of anything so long as the weigh pan (the platform upon which you rest the stylus tip when measuring VTF) is nonmagnetic.

I use Riverstone. It is not hard to set up - I turn it upside down to install the stylus platform.

Accuracy can be verified with the two included weights. 

That Rega has a small target to lower down onto.

It is not always easy to see the stylus tip, so I like a larger surface to lower the stylus onto, doesn't have to be perfectly centered, the downward force can actually be measured at the corner of the cartridge body, it is the same,