Did I do a good thing or not?

Hey, at least it wasn't a flavor-of-the-month $3500 MC made from mandrake root.

With its coil inductance of around 400 microhenries it won't have the speed and snap on transients of lomc cartridges. I have one NIB and a spare Jico stylus. Arm choice is important! A Grace 707 with its straight lightweight arm tube would work well with the V15's high compliance - I have two! A Denon 309 arm would also be a good choice. 

Back in my early audiophile years I tried an M91E, a Stanton 681A, and an Empire something in my Dual 1209, because they were $5.00 each at Korvette, and I was curious. I greatly preferred the Stanton. Later I enjoyed a B&O SP12, an ADC XLM and Sonus Blue Label before my first MC,  a Denon DL103S. I never went back to Shure until I tried an M95HE a decade or two ago…again, dull and lifeless to my ears. More recently, a V15 IV came my way, and I got Jico SAS stylus for it, to go on a Well Tempered TTTA. Finally, a Shure I could enjoy! I hope you do too. I now am using an AT OC9 XML with even more pleasure, and a newer phono preamp (Pro-Ject PhonoBox DS3), which gives me lots of loading and gain options I never had before.

I too hope you enjoy the Shure, despite my pessimistic comment.  Pay no attention to Jason, who even got the inductance of the Shure wrong.  He stated it's 400 microhenries when in fact it's 1000X higher than that, at 400 millihenries (actually, Shure say 500mH).  But the good news is inductance is only one factor that might partially affect transient response.  Other factors (moving mass, compliance, etc) are actually in favor of MM and MI cartridges over MC cartridges in terms of transient response.  Also, as someone else pointed out in another thread, inductance acts through hysterisis, which is only a factor for certain coil structures. Back in their heyday, the Shure V15s were known and advertised for their tracking ability.  And indeed they measured superior in that regard. Tracking ability also is a correlate of transient response.  So, listen for yourself.

Brain fog in the morning made me misstate the inductance of the Shure's coils. I know the difference between micro and millihenries. Anyway, I'd rather listen to a low-inductance Grado MI than a Shure. That high coil inductance makes MM's very sensitive to cable and phono stage capacitance.