I've been researching/reading/trying to decide about an AR15 with either a gas piston or direct impingement design. I think the biggest question I have is how much more weight will the piston design add. I'm not a weakling but every bit counts. Thanks!
I had a Ruger gas piston AR and loved it, but it was not just too heavy, but too front heavy, making it not feel as balanced. I thought about a Stag model 8, but DI works so well, I sold the Ruger and focused on a couple lightweight DI builds. They are simple, incredibly reliable, and light. I haven't looked back.
This is probably one of those things where you'll be better off physically holding the rifles side by side in a gun shop. I really prefer a piston over DI, and think the weight difference in my LWRC is minimal for what I gain. Some others (like the Ruger) feel much more front heavy to me. But if balance / weight is your main concern, you might take a look at that Tavor. It's the only rifle I've ever had that is so well balanced, I can run it one handed.