Pretty much that's all you can really expect because skinnier tires change your sustained or top speed too much. As you've mentioned, the lower weight only changes how fast your wheels can accelerate pos or neg because of reduced inertia. Difference in rolling resistance is probably trivial. There is likely a big difference in aerodynamics, but that doesn't really matter until you're going like 20 MPH.
How much do you want to spend on tires? Panaracer Tserv are pretty nice, but they're around US$40 each. I think you can get it in 1.75" which is fairly close to the 700x42 (1.6") tires that I'm running on my rigid hybrid commuter.
Believe it or not, cutting out one or two pounds from each wheel on a car makes a noticeable difference also.