I have a Typhoon G (same as Q500 but with a gimbal for a GoPro), a 3DR Solo, a DJI Phantom 3 Professional, and an Autel Evo, and have used them all for commercial work. It just depends on the type of work. My Typhoon was my first, and I did video as a sub for other company's projects, part of a political commercial, misc content for various web productions, and several land sale videos with it and had good results. I think the GoPro Hero 4 Black camera it was carrying is a better camera, but I don't think it is that big of a difference.
The only problem with the Q500 I see is that a lot of commercial jobs out there are targeted towards DJI drones, and some will have standards based on the quality they want, and because they don't know Yuneec model comparisons, they will just list requirements for DJI models and you may be out of luck.
If you're just dipping your toes in the water, your Mavic Air probably has a slightly better camera then the Q500 4k, so you could try some doing work with that. And I think the range would be similar as well. Also, your Mavic Air will be compatible with 3rd party software which the Q500 is not.
If you haven't purchased a Q500 yet, I would also recommend shopping for used Phantom 3 Pro/Advanced, or early Phantom 4 models (with the smaller chip) which might be available for similar prices, and have better range and a lot more flexibility than the Typhoon. I think several others also mentioned the Typhoon H, which I believe is a better camera than the Q500 for not much more money.
But it all just depends on the type of commercial jobs you are doing.
If you are wanting to do site surveys though DJI is going to be tough to beat, because you can use 3rd party software for a complete solution from control app to processing. I think your Air is compatible with most of them. I don't think there is a way to program a Q500 for site surveys but I could be wrong.
I know a lot of realtors swear by the Mavic Air as well for portability and it's a good size for indoor videos as well, but a Q500 4k would be more than good enough for most realty pics/vids.