we know! Problem is IN GAME the sdf-1 would be tiny. Plus I found out the civillian city was actually iin the REAR compartment in cruiser mode. 70,000 non-crewmembers relatively jammed into one section of the ship. Plus all the space required for 212 native fighters, a destroid contingent, on board military basic training facility, munitions factories, repair bays, ect...
Just cause it was stated as 3/4 of a mile, in MANY scenes of the animation the ship was showed to be WAY larger and the worse culprit is the landing sequence... Originally there are 7 landings bays per side of the bow struts. Trashman modeled 4 per side that a veritech can land in (though I would like to see them go deeper and have fighters pour out from them to atttack!

) That alone should show you the scale of the ship as it would be in real life using those landmarks.
I think the original battlestar galactica also suffered from the "floating scale" issue. We know how wide the landign bays should be cause of HOW the vipers launch. They launch from the SIDES and only land on the visible runways. As there are huge bays behind the tubes and you can clearly see the other vipers in their launching berths the two side pods must be enormous! I'd say a good size for Galactica would be around 2000m NOT the 650 meters cited by many referances cause at that size would make the landing pods unworkable for the amount of room we know they utilize sideways !!!
l8tr!