Here is an article of the standard DL connection F meal and service, this one is on a route that UA competes on [LGA-ORD shuttle]. I believe all flights over 900 miles and "competitive" routes such as LGA-ORD will receive a cold meal and yes there are meal choices.

http://savvystews.com/2013/09/first-...e-nyc-chicago/

I surely enjoyed sipping my tea [DL serves Bigelow which is not too bad for airplane tea] out of a proper ceramic mug when I did PIT-LGA/JFK frequently awhile back, I hate the Styrofoam cup. Whether you are on a mainline bird or a regional jet, everything will be exactly the same service wise and hard product wise [even the F cabin seats and the Y seats are standardized and consistent], the only difference is no power outlets/in-seat IFE on the RJs. That's all.

P.S. the biggest disappointment [trivial though] for me is DL got rid of the Sun Chips from the snack basket and replaced it with Fritos