Absolutley nothing....
I originally was going to order a 1LT with only the upgraded stereo and the convenience and connectivity package - THAT I would have regretted....
I wanted a sunroof but the $900 seemed a bit much...
Lucky for me I tripped over my 2SS loaded with everything (except insanely priced rims and GFX) and I'm SOOOOO happy I did - I couldn't imagine having to settle for less
That being said, get what you want as long as you can afford it - I'm lucky I had that option but...if you aren't rolling in dough like me (I say that sarcasticly - I had to take my divorce money to pay for this car and because of that I only ended up with $22 back on my taxes...I have my car but otherwise
....LOL she's worth every cent I don't have
) then get the options you can't install later. A lot of things can be added after - but things like a sunroof can't!