I'm coming out of the flea market closet. I am sort of a fan of these types of things.
As far as flea markets go I like them because they are electic gatherings of things you don't see in stores all the time. Having said that, 60% of the flea markets I've been to I've completely hated, felt like it was a waste of my time and energy - but I've found just enough items (to buy, or just even to look at) at the 20% that I felt I couldn't get anywhere else that make me venture into these places.
The Mesa Market is not your average Flea Market. There are some touristy type things, sports memorobilia, games, even a few Cacti growers,and yes some of the booths have junk but it's fewer and far between. One thing to note is that there are a few booths that seem repetious - and in that the pricing is different and the quality of the product is different. I highly recommend walking the whole thing first before buying what it is you want, making sure you get the quality and price you want. Sometimes you can haggle as well with one, vs the other.
If you have a aversion to flea markets I'd still give this one a try. On the weekends they even have live music and in the middle of the place, a little place to get food if you are so inclined in the circus-festival food type.