I bought one of these off of Amazon for $99. I wanted a Big Boi but they were a bit more pricey and out of stock. I've used a leaf blower for years, and will still use it for the majority of the body but the Sidekick has some clear advantages. I don't have an air compressor, so I decided to get one of these for engine bay debris cleaning, drying and door jams. It works extremely well. The air is more concentrated due to the cone tip. It does a great job of getting rid of sand and dirt in a dry engine. It also comes with an attachment that can widen the angle of air coming out.
I also picked up a Worx Hydroshot, mainly for winter time and for occasions where I don't want to do a full wash. You can use 1 - 2 gallons of distilled water and not have water spot issues. In the winter it's great for cleaning engine. Just grab a bucket, fill it and you're good to go. No hoses to deal with.