Looks pretty but will split about 5 times faster than regular brass. 

I’ve shot gazillions of rounds of nickel plated .357 Magnum.  Some have been used so many times the nickel about worn off.  I’ve never had them ruin the die.  Of course, they are in a carbide sizing die.   

On rifle calibers I sell or trade away all the nickel plated brass I acquire.  I’ve never had it embed anything in the sizing die, but it splits way too easy.   

I have bought a bunch of used dies that are nasty inside.  To clean gunked up sizing dies, I use automotive rubbing compound (mildly abrasive for cleaning car paint).  A little bit on a patch held in a split dowel, and spun with a cordless drill cleans up even the nastiest dies in less than a minute.  After hitting the die with the rubbing compound, I clean them well with brake parts cleaner, and lightly wax so they don’t rust.

Still using my nickeled .470 NE brass reformed to no.2 musket - however, the nickel has worn off, I presume due to many ultrasonic cleaning cycles.  But it still keeps on going....  No embrittlement or whatever.