Ill post my reply as someone who just finished primary. I went into primary with my multi-commercial/instrument and from talking with the other guys around me, it absolutely helped out. Alot of instructors will tell you that it doesn't matter and maybe in the big picture it doesn't...But to give you an idea of the differences, while I was learning how to fly the T-6, my peers were learning how to
fly an airplane. When I was learning all about the FMS and the cool things that the T-6 did differently from some of the other aircraft I'd flown, my peers were learning how to read an approach plate. It's the little things that seasoned pilots don't recognize, because they may have forgotten what it was like to learn them the first time. Things like how to write and fly at the same time, what to say (and not say) on the radios, HOW to talk on the radios, how to read a plate, or file in the air, or even just knowing that you can close a flight plan with a FSS. The biggest advantage you have by going through primary with decent prior time is the confidence that comes with knowing that you can fly, and now it's just a matter of learning how to fly a specific airplane in a specific manner. If you approach primary with the mindset that you're already a professional pilot and that you should fly the T-6 like a professional pilot, you'll do well. Know that once your peers find out about your experiance, they'll ask you questions and expect you to know the answers. You should seek out opportunities to help them with things you know. Help your friends, pay attention to what the IPs do, and have fun with the flying. You're flying a small, relatively lightweight 1,100 horsepower two-seater with a bangin' air conditioner. Don't F it up
-Matt