I've had the Midwest Industries Gen2 SS series handguard on my AR for about 6 months so far and figured I'd do a product review since there seems to be a lot of questions out there about these rails.
-Lightweight (7''-7.1oz, 9''-8.3oz, 10''-8.6oz, 12''-9.3oz, 15''-10.9oz)
-Made of 6061 anodized aluminum. The anodizing is holding up well so far.
-Made in the USA.
-The narrow profile helps you really "grab on" to the handguard and stabilize the rifle.
-Comes with 3 2.5'' rail sections for mounting whatever toys you have in mind. One of the rails has an anti-rotation QD socket for sling mounting. There's also a bipod stud that comes with the rail.
-Comes in OD green, FDE, and black.
-A barrel wrench is included (not the best but it is functional).
-The slots in the rail allow for good barrel cooling. The holes just below the rail also help the gas tube cool.
-The anti-rotational system works as advertised (better explanation/visualization in the video).
-The rail sections are contoured to the shape of the rail and mount flush so there's less chance of snagging.
-The barrel nut has to be replaced. I don't think it's a big deal but it's just an extra step vs some competitors out there.
Here's the video review with a little shooting and a discussion/demonstration of the rails' properties:
MI Gen2 SS Series Rail HD Video Review Link