I've been to My Mom's Thai Kitchen or Thai Basil once a week for the last 3 months when I travel to Phoenix. After going to both time, My Mom's is a solid choice. I will say that I prefer Thai Basil though.
Pom and Austin are very nice and attentive. When it's busy, the service slows down a little since it's a small shop, but otherwise I've never had any issues. The flavors in the Tom Kha soup are good, but they aren't quite blended together that well. You get highs and lows of sweet and lemongrass, but not one consistent flavor. The BBQ pork is tender, but a little overly sweet. .And it's served with a salad of iceberg lettuce and a thick orange dressing instead of steamed veggies. I've also had the mango salad, the papaya salad, the beef salad, the beef skewers, and the grilled eggplant salad. The portions are generous, which is great.
Overall, it's a solid option, but if I'm in downtown, I'll choose Thai Basil first.