Benefit of low output moving-iron Grado ?

A stylus has about a 2000 hour life span so you do the math! The lower output Grado has less windings and your preamp might not have enough gain.
You would have to find out the input sensitivity of your phono(.5mv or less)to make sure the lower output will work!
I use the 1.5 version of the Sonata which is called Sonata VPI!
I don't think your system would benefit with the more expensive Master!
For $400 the Needle Doctor will give you a new one with trade,they do not replace the stylus on them,they just replace the whole cartridge!
BTW: I am a big fan of Grado I have been using them for over 30 years!

By using a low output version, I suspect, you will hear very little if any difference in your system. I would check the capacitance and make sure its within the recommended bounds. Check your setup again and again to be sure it was installed correctly.. Call Grado for any hints.

Not sure how relevant my experience would be to yours, but here goes for what it's worth. I wanted to upgrade my Grado Sonata high output and so I traded it in to Grado for a low output Master 1. At the time, I was using a Music Reference RM5III as a phono stage, whose owner's manual said .5mv was the lower limit of acceptable cartridge output. Sound with the Grado was anemic and shrill regardless of whatever of adjustment was applied to the RM5III, obviously a mismatch as the RM5III sounded excellent with the 5mv. Sonata. So, I researched my options and purchased a Sutherland PH1-p, which should have worked fine (if numbers and specs were all that mattered.) That was also an ultimately unsatisfying pairing, still a bit lifeless and lacking in drive and "cohones." At that point, I took a big gulp and upped the financial ante with a RCM Sensor Prelude. This finally got me into the realm of hearing what improvements the lower output Master 1 cartridge was capable of bringing to the table vs. the Sonata. In spite of the Master 1's greater refinement in high frequency response, imaging, and wonderful delicacy of small details, the Sonata still had a greater "fun factor" and was more propulsive in the nether audio regions. Not a uniform, across the board improvement IMO. At this time, I use the Grado intermittently in rotation with an Ortofon Kontrapunkt H, which seems to have more drive, jump factor, and electrical output in spite of the fact it is rated the same output as the Grado.

Thanks, Photon46 for the valuable info; very relevant. In fact, since my initial writing I realized that an operative consideration in all of this is the phono pre-amp. I looked around a little and read about the Grado Ph1 MM/MC preamp which seems like a deal and would theoretically be pretty well matched to a Grado cartridge. Since you also mentioned the fallibility of theories, perhaps someone could vouch for the particular combo of Grado Master .5mv and Grado Ph1 phono preamp? I live a distance from anywhere I might be able to audition stuff (and we have no car), so I rely a lot on research on the web.
Another side question I've got is about cartridge setup. I see that there are two screws on the top of the tonearm which go into the cartridge. If the cartridge I buy weighs exactly the same as the old one, wouldn't installation be as simple as removing the wires from the old cart, unscrewing the screws, and installing the new one in the same way? I wouldn't need an entire setup procedure from a professional, would I?
I have to admit I've never even heard a low-output cartridge and I'm going on research alone that it might be something I'd like. And with Needle Doctor's deal on trade-in cartridges along with the still-affordable phono pre-amp upgrade, it seems doable and worth the potential error in judgement. I could always trade-in the Master Standard for a Sonata Reference for the additional $450 if I'm unhappy, I suppose. And it's not like that's small change for me either, that's three weeks salary! I guess I suffer from the bug like anyone, and I find great enjoyment in listening; always have. Thanks for the heads up on the "cohones" issue! Very glad to have gotten these responses folks, thanks....

No professional setup needed! Just swap cartridges!