scientifically speaking, turbos are more efficient. turbos can make almost unlimited power and are more driveable on the street when you're not in boost. i'm guessing fuel mileage is probably better also. can't say for sure, but it seems like turbos have much more top end where a blower setup will give you more mid range.
with turbos, the initial hurdle is getting all the turbo plumbing and necessary prereq's. though once you have all the plumbing setup, you have tons of turbo options to choose from and switching to other turbos is simple and can be much cheaper(although with TT's its 2x the cost) than getting a new blower. however, blower setups are much simpler and you can retain all your bolt-ons, which is why i think most people go this route.
i also have a turbo supra with a mild 60mm turbo and its plenty of fun to drive in the upper rpm band. hoping to go with a big single setup on my camaro in the future. in my opinion, i don't think the benefits of twin (maybe slightly quicker spool?) vs single is worth the extra cost of getting 2x everything (extra plumbing, heat, space requirements)
bolt ons, tune