This branch of Minthiha (I think there is least another branch in Mandalay) is one of my favorite stops for good meals. Yes, it's more than just a teashop!
While Minthiha DOES have very good tea (the sweet, hot brew so commonly found in this country), it's the food that really distinguishes the place. In the morning you can try local noodle dishes like Mondhi or Ohno Kyauk Swe. This is the REAL Burmese food tradition! The rice salad (fried rice with some veggies) is also very good, as are the side dishes like the Nan Bya (Flat bread with beans) and fried vegetables.
Unlike some local tea shops there is an English language menu at each table. But a warning about those tables: they are small and the seats are usually tiny wooden stools, so the comfort level is not what most Westerners may be accustomed to. But the VERY low prices and high quality of the food make up for such discomfort. No AC, but plenty of ceiling fans, and the now have Wi-Fi for customers.
This place is almost always very busy and there are times you will have to share a table with another party, But Myanmar people are very friendly and you might find yourself striking up a conversation and making a new friend. Another perk of going to Burmese teashops. A highly recommended activity.