I think it depends on your expectations, but also on your body type (oily, dry etc.), the salon you go to and a number of other variables. I've used Mystic Tan off and on over the last few years. I like it because I don't have to have someone else put it on me -- it gets all the hard to reach spots, it's quick -- just a couple of minutes of spray time, and the color looks good on me. You have to experiment a few times to figure out angles to put your hands etc. and how to dry off afterwards -- too much pressure (can causes streaking), not enough pressure. Also, sometimes the sprayer can drip on you right after it stops spraying and that can leave a line. The spray does have a smell to it -- some people notice it more than others. It also leaves a little color on your clothes that you put back on after you are sprayed. I've been able to get the color out of everything, but one bra and a pair of undies. I normally go two days in a row, to create a darker tan if I am going out of town. One of the major downsides is it fades fairly quickly, especially if you shave your legs each day.
For that reason I've been looking around for a self-tanner that is easy to apply and that I like the color of so I can take it on trips with me. My current favorite is a product by Fake Bake. I saw it mentioned in a magazine and it said Kelly Ripa uses it. My husband puts it on for me and and product is good. My only problem is it takes longer to dry than Mystic, and takes longer to apply -- maybe 20 - 25 minutes to get it rubbed in well.
If you have any other questions, let me know.