I bought three compact frames when they where 49.00

Thinking of grinding or filing the finger groove nub off ofr one.

If you did what did you use and how did it turn out ?

I'm thinking a triangle file would work best.

I prefer a Gen 1 or 5 type grip with no grooves. Really like my micro grip

Yeah, last night.

Ground it off on both my compact and fullsize including removing some of the hump on the backstrap.

Sanding disc with my Dremel, just take your time.

Not only did I grind off the finger group, I cut the damn grip down to fit G26 magazines

I clicked this wondering if you were talking about the little nub on the end of the trigger bar that interferes with trigger reset on some non-dagger slides.  

I had that happen on one of my friends so I replaced the trigger bar and shoe with a cheap P80.  

Then it turns out the magwell was out of spec so I put the original back in and I still need to get that returned for work/exchange.