Well… As I was going to say… Before Noah spoke, the general rule about Ram, ever since computers were invented… The more ram, the better.
I would have suggested, that if that's the only configuratiion you can work with, then go with the larger amt of ram. Upgrading the Lenova might cost you the extra 100 to double the ram, I'm not sure. Are you buying from store or online. You might check to see how much it'd cost to max out your ram. Maybe you can get a deal on it.
Your graphics and HD sizes are the same, so no comparison there. Then what would you check on?
For me, most of what I want in a laptop depends upon how it's configured on the OUTSIDE. But then, I'm not a gamer like you are or want to be. It depends very specifically how the keys are, how they feel, how my hands sit on the keyboard. I have to have the old style curved keys, I can't use the more modern flat style that most modern laptops have. But that's just me.
Other thing is that most modern laptops are pretty well built. It was 20-30 years ago when it depended on how much you paid for a really good laptop. There used to be great differences between a really cheap and bad laptop and a very good an expensive laptop.
Technology has increased so dramatically that you can spend hundreds less and still get a top of the liine computer. But gaming is different, it might come down to which chip is the best.
So there's actually little to choose from to compare for each laptop. As I said, it depends more upon the outside of the laptop for me. But i still say that the more ram the better. It won't hurt to have extra if you need it, rather than need it and not have it.