The nice thing about hot air is that its just air - this means there's no physical 'tip' nudging the part to heat it up. This is great for delicate components. Another thing is that you can heat up an entire area at once, great when you want to rework a small leadless part because the pads are underneath the chip. The annoying thing is it takes a long time to heat up a board especially if there is a ground plane involved. You can try preheating the board if you have a preheater (basically a small reflow oven works fine).
We decided to go with a Hakko pencil tip hot air station. This station has some things going for it: there's an internal pump, its easy to use and it has a fine tip for small component rework. We picked it up off of ebay for about $150 which is lower than new but worth the risk of it not working out. We recommend getting a non-'chinese clone' air rework station since its common for a poorly made one to work ok at first and then die 6 months later because the pump is low quality, or the heater gets damaged. The old 'black box' Hakko's are discontinued and replaced with the new violet/yellow FX series, so it may be easier to get them off ebay for a discounted price
However, we recently decided its not 'good enough' for us so we bought a Hakko 852 off ebay for $400. We'll post up here when it comes in about whether we like it more.
We use the Hakko Hot Air station for SMT rework, especially removing small resistors/capacitor or removing/reflowing ultra-small QFN's or UDFNS.
This is a nice video with a lot of details on using hot air reflow. Its slow but it works!