Well they have helped me out. Honestly I used to hate the Gears online mode. I loved the campaign and just really hated the online. I started like 5-38 on my first few maps.
Since GD actually gave me these tips, I do much, much better. I'm not great by any means but I can hold my own and get some kills, back people up.
I admit, to get into the game I used the C&C strategy, it's noobish but man I was chainsawing through some niccas.
Then I gradually got better with the shotgun and doing the Melee/shotgun tactic. So listen to these tips, they really work. Now I love Gears 2 online! In fact you wont see me much on MW2 until they fix all these damn glitches.