I have both a scroll saw and bandsaw, (both Delta, BTW) and use them pretty much interchangeably for modelling in the size I work in (up to 1/4 scale). It's easier to cut tight curves and intricate pieces with the scroll saw, and thick pieces and long straight lines are easier with the bandsaw. If you need to cut openings, such as the "inside cut" on a fuselage former, then a scrollsaw is mandatory. You drill a pilot hole, take the blade loose from the top arm, stick it through the pilot hole, reattach the blade, and complete the cut. Can't do that with a bandsaw.

The other thing to consider is the "relief", or distance between the blade and the top arm support; on tabletop models, the scroll saw usually has more relief than a bandsaw of the same general size, allowing you more room to cut long pieces across the short dimension.

Scrollsaw blades are, for the most part, thin and delicate, where you can get bandsaw blades in several thicknesses, as well as metal cutting blades. If I could have only one, I'd probably go with the scroll saw, just to be able to cut fuse formers and wing ribs- the tight corners.

I like my Delta saws, both tabletop models, about $200 each.