I have the Gen 1 DMR. I had an 18" barrel vs 16" of the Gen 2. The former is heavier due to barrel and different forearm hand guard that is lighter on the 1. Butt stock also different . Barrel on Gen 1 is threaded with no muzzle flash or brake. These changes alter the balance and weight of the gun.
Can't talk to the differences with the patrol model except for butt stock, hand guard and shorter barrel.
My Gen 1 DMR is very accurate. Suitable for bench, long distance and counter sniper shooting. Gen 2 may be more suitable for hunting.