I am on a waiting list for a currently unreleased bike. Here are the details, based on the picture below.

The bikes X1 and X2 are the bike I need to decide on size. Not sure if I want a 19" or 21"! It is an unreleased bike, so a test ride is impossible. There are no dealers nearby anyway.
It is 29" wheel, with 150mm travel, front and rear.

Already owned bike #1 is the one I can't seem to get to fit or feel proper for some reason. 120mm travel front and rear, 27.5+ wheels.
It came with a 50mm stem, which I have bumped to an 80mm 7*stem, 777 bars (but I think I want to go to 750). I think I've got it close to feeling like I want.

Already owned bike #2 is my XC machine, and I love it. It is 29" wheels, designed around 100mm travel front and rear. I did put a 120mm fork on it. 80mm 0* stem, 750mm wide 15mm ride bars. Stem is slammed to the headset.

Already owned bike #3 is my everythin bike. 29" wheels, designed for 140mm front and rear, but I have a 160 in the front. 65mm 0* stem, 750mm 15mm rise bars. Stem is currently 30mm from the headset, but I have been tempted to lower it a bit. This bike is awesome in every way. Love everything about it, and every time I ride it, I am more impressed with how it performs. Uphill, downhill, flats, rocks, chunder, whatever.

Some of the specs, looks like a 19" would be perfect, but a few, 21" would fit. Two of the bikes I have are 19", one is 21" (as shown below).

If more details would help, I will add. Just looking to see what a consensus is for ordering size!

New machine, but sizing questions.-bike-geos-all-comparison-2-.jpg