Leaf blower for me, but I'm an enthusiast with one car. If you are doing more than 10 cars a week, per your post, a master blaster is probably well worth the investment.
The Sidekick is on sale at AGO for $79.99 The Air Force Blaster is on sale for $229 on AGO. I have the Sidekick for the accuracy. I bought the electric leaf blower is $31.99 at Wal Mart. I would go for the Sidekick mainly for the price. If you want more powerful air blowing then the electric leaf blower is good. However, the Sidekick IMO can do the same thing as an electric leaf blower as you can be more accurate with blow drying the car. The Sidekick really blows air hard enough to dry the car no problem. I keep the electric leaf blower just in case I might need it plus I probably couldn't sell it for more than $15. I would rather keep it as a spare tool I may need in the future.
I can't see spending the extra $150 to dry the car. I am sure there are more features with the master blaster and it can vacuum too. I already have a powerful vacuum to clean the interior. rops: