FWIW, Stick with a designated platform. Avoid the "conversions",....
My Sig556, has very few parts, even for a gas operated piston rifle, it is also has a two stage position adjustment, which I have never had to use even after a 500rd shoot.
If it is for you, get one, the "conversions" seem the fly in the ointment for non gas operated rifles.
from Overlord,
Piston ARs have more parts than DI AR. In general, more parts equals more chances for something to go wrong.
Gas Piston guns are generally thought to be less accurate than DI guns (due to more moving parts).
Piston guns are more expensive currently than DI guns.
*subject to brand, and opinion, and availability, which is good right now.
The same "opinions" regarding accuracy have been stated about chrome-lined barrels also.