I have two 9mm Shields. I have the Maguts +1 on each 7-round mag and carry that in the gun. 100% reliable through hundreds of rounds each.

Both of my 8-round mags have the +2 extension giving me 10 rounds in my backup mags. I use these 10-rounders at the range more often so I load a little less frequently. I have many 100’s of rounds through each with no problems.

So I carry 19 rounds total, 9 in the gun and the 10 round backup mag. For only one reload that’s a fair amount of ammo for a very concealable gun.

Maguts: expensive, but worth it IMO.