Just got a P30 and I've been trying different combinations.

According to the sizing charts, my hand/glove size is barely a medium so I initially ignored the large backstrap.  I decided to give it a try and really like the feel of the large backstrap with the medium panels on both sides. It doesn't seem to increase the trigger reach much but the larger bump forces a higher grip/locks the gun into my hand a bit more than the medium backstrap.

I haven't had a chance to shoot it with this setup but hope to do so soon.

Anybody else with medium-ish hands running the large backstrap and if so, how are you liking it?

A piece of advice is that what feels the best in your hand doesn't necessarily mean that's the one you'll shoot best with. When you go to the range, take all of the inserts and the tools you'll need to swap them out.

You might be amazed at what you like.