Seems better than stock but has drawbacks - Midwest Industries SIG Rattler M-Lok Handguards

This handguard is about .7oz lighter than the stock one and provides better look. It is thinner and gets rid of the QD rings so it is more comfortable to hold.
However, the gas adjustment is much less accessible and as other reviews mentioned it won't work with some if not all suppressors. You will also have to uninstall the handguard if you want to change your muzzle device.
Additionally, the upper m-lok slot is pretty sketchy to mount anything. The rail that mounts the handguard is right behind which interferes with the lock keys. You probably either can't fit or won't be able do a 90 degree rotation on the m-lok keys to fully lock your attachments in place. The lower front end has a 45 degree angle that just perfectly prevents you from mounting any longer 1913 rail pass front of the guard, which you can do with a stock guard.
FYI, the retainer clip at bottom is screwed in place permanently and if you try to unscrew them it will void the warranty.