Turbo's are cheaper, no worry about belts, pinned and double keyed cranks, belt slip, or pulley alignment, also very easy to add an intercooler into the air path.
I was looking at a screw supercharger for a project and it was going to be like 5k just for the unit. I can buy 2 decent turbo's, intercooler and wastegates for 4000.00 that will make more power.
The down side is looks and sound though, the classic supercharger type of install always looks and sounds better.
I became a turbo believer first time I made a home built setup that made 365 rwhp out of 80 cid and basically had no idea what I was doing back then.