Originally Posted by pvaudio
It depends. If you only need it for tennis, then heat gun absolutely. It will do your job perfectly well. However, and take this from someone who uses them frequently, they aren't forgiving when an unattentive person is using them. As someone else said, take all of the heat generated in 5 minutes by your blow dryer and that's the normal flow for a heat gun. Like many things in life, even though it's the proper tool for the job, you do need to understand how it works to avoid damaging something.
True, you'll develop bad habits with a hair dryer. With any heat gun, give the piece some working distance, and rotate constantly, you don't actually want huge amounts of shrinking on one end of the tube, or the weight distribution will actually get a little bit wonky.