Carburetor selection choices

[surviverguy]

I've noticed that the GS450 was produced for about eight years. During the eight year production at least three different carbs were used. 1980-1982 used a Mikuni with relatively small slides and a needle that's straight with a sharp pencil tip. 1983 models got carbs with larger slides and long needles with lots of tapering. Some models got "pumper" float bowls and "pumper linkage". 1984-1988 got similar to 1983 minus the pumper.
Besides the differences in appearance, how are they different? Are the pumpers better performers? Are the later models with tapering jets giving better midrange performance? Are there downsides to the later carbs vs. the earlier carbs with straighter needles?
My 1980 450 could get any of the different carbs. Is there a "best" carb? Are there pluses and minuses? Which carbs would you choose to use with K and N pods? Fuel economy and best midrange performance is my desire not full throttle top speed racing.