150 grain subsonic? That's a very light bullet for a sub. Also, if it's in an AR, that will be hard to get it to cycle.
The differences are simple. The subsonic ammo runs below the speed of sound (which is about 1100 fps) and is a reduced load. The supersonic ammo will be a full power load running at top speeds for that bullet.
Depending on the rifle and ammo, your sub rounds will impact about 6"-15" lower at 100 yards than your supersonic ammo. It's simply due to the much slower round. You will want to sight in for 1 or the other. If you plan to switch back and forth, you will need to change your scopes zero each time. Having a mil or moa scope with turrets helps this transition.
Your 125 super ammo will impact high about 6"-15" above where the 150 subs are sighted in at. Let me know if the 150 subs will cycle, I'm curious. And if they do, how clean/dirty they are shooting suppressed.
IMO, the subs are for fun, and the supers are for hunting. Shot placement and knowing your bullet trajectory in the subs is critical to making lethal shots. A 300 blk out sub round is about like shooting a 45 ACP, instead with a 308 bullet that doesn't expand.
I have lots of ammo options available below.