Coilovers will generally make the car feel a bit sharper, but the ride a bit firmer, right? But there are brands out there that are better suited to daily driving than others, and aren't as harsh?

I'm not 100% sure, having never had coilovers, but I imagine the OP would like to know.

All I know is that it's worth saving up for coilovers rather than getting springs and new shocks. The flexibility, and guarantee of perfect fitment, seems worth the price of admission.