I used to live in China (a few decades ago) and at the time never saw a flat bottomed wok. Never even heard of them, nor a wok ring for that matter. People just put the wok on the gas burner directly.
Surely flat bottom or wok ring are only needed if you have a completely flat surface like an electric stove (? Not an expert here, but just never seen the need).
I later lived in India for several years, and ended up much preferring karhai/kadai to a wok. They are actually derived from the wok, but a bit smaller, making them easier to both store and handle. I have several, both round and flat bottomed, and use them pretty much daily, round bottomed far more than flat bottomed.
Round bottomed you need far less oil and cooking liquid.
The pan I use the most is very thick stainless steel with a copper bottom, doesn't have any patina on the inside and I can clean with steel wool and can chuck it in the dishwasher. Second most used is thick carbon steel which I seasoned myself, must of course wash gently by hand and dry by heating briefly on the stove top after washing to prevent rust.
As I'm sure you know, a non stick wok is a ridiculous idea. For most Chinese food the pan needs to be hotter than non stick will allow.
Btw, if your food is releasing water, there are several ways you could be going wrong:
- Pan not hot enough to start with (sometimes saw woks actually heated to red hot in street markets in China)
- Too much food added at once, which lowers the temperature
- Too much food being cooked in the pan
- If you're cooking something that will be fairly big in the amount of food, don't hesitate to do it in stages, take out the cooked ingredient and set aside, cook the next bit, then recombine all the cooked ingredients in the wok at the end.
E.g. I relatively often cook a dish learnt from a Vietnamese-Chinese friend where you fry thinly slivered ginger till crispy, set aside, fry very thinly slivered green capsicum till just cooked, set aside, (not with the ginger as it will lose its crispiness), then add cook a slivered clove of garlic, then immediately add sliced chicken, cook, then add capsicum back in, add fish sauce and soy sauce and water if it looks too dry, then add in the ginger back in just before serving it out. Total cooking time about 5 minutes.
You can see here the advantage of the pan being round bottomed because you need to add a tiny bit more oil at each stage when you cook the new ingredients and this way the amount can be minimal.
Hope this helps!