I've shot about 500 rounds through one, and was pretty impressed with the weapon.
Positives:
The safety/selector is right where it should be, you can move it without breaking a firing grip on the weapon, and it is SAFE-SEMI-AUTO. It is good to have a semi position with a the high rate of fire of the weapon.
The weight is balanced well, and aids in control when firing full-auto.
Cleaning is a snap, pull the rear receiver cap and hinge the receiver/barrel group down, then pull the bolt out to the rear. Similar to the M-16, without the dirty gas operation. Just pour hot water down the barrel, swab it, wipe off the bolt, reassemble, and you're back in business.
Negatives:
The mag release is unusual, you must lift the lever instead of just pushing forward with a finger.
The drums rattle when loaded, and you may go through a few before you find one that your particular weapon likes, but if you use the 35 round stick mags this is a moot point.