I had a 1LT 2009 C6 and loved the car but always missed the upgrades that came with a higher trim level, but it was my first Vette and it was a Corvette. When I purchased my 2015 I knew, long before I went to my dealership, that I wanted an optioned out model. The dealer had 2 on the lot. I had a look and although beautiful cars, they didn't have the things I wanted. The salesman asked if I saw the one in the showroom. The deal was made the next day. My car is a loaded up 3LT and I would buy the same trim level and options all over again. Look closely at the standard features on each of the trim levels.
My seats in my 1LT 09 were mulan leather, which is equivalent to Spam. It is ground up leather scraps that are glued and bonded together again and they can still call it leather. It looks good but in 5 years my 09 seats were wrinkled, ribbed, and showing wear spots, one that I had to have professionally repaired when it turned into a hole. My 3LT C7 are Nappa leather. (real full grain, not split or bonded leather), and look exactly like they did in the showroom after 5 years.
The Heads up display was new to me as well and I love it. You get use to it easily and it keeps your eyes forward.
The extra leather trim interior wrapping is just looks, but it looks damn good.
Upgraded Bose sound system, including GPS nav, (Apple Car play and Android Auto in the 2016 and newer)
Heated and ventilated seats
Memory seats and steering wheel
Front curb camera (a must have IMO)
Universal home remote
Performance Data Recorder (a must have great upgrade option IMO)
That's all I can think of at the moment, and this is certainly just my opinion. The 1 and 2 LT's are still wonderful cars but definitely look close at what you want in your ride.