Personally, I won't use them. You don't know what you are getting. You may be getting a somewhat ok 20A battery, or you may be getting a low end 10A battery. You just never know what they are rewrapping that week. If you buy a name brand battery(LG, Sony, Samsung, etc) from a reputable source, you know exactly what you are getting.
Having the additional wattage lets you try more power if you want to. If you never need it, you will just have overhead and not be running the mod near its limits. My rx200 can go all the way to 250w, but it rarely ever sees over 100w anymore. I don't consider it a waste. I just get to go longer without charging. Off the top of my head, I don't know of many regulated bottom feeders. Personally, I have tried a mech that was a squonker and didn't find it all that great. I prefer a tank where I fill it with juice, build the way I want(I use a griffin 25), and then just refill the tank occassionally. Typically, a tank will last me an hour long drive while chain vaping. That is more than enough for me. That is just my preference, though. Some people prefer squonk mods. Others prefer tanks. Others prefer RDAs. It is just all a personal preference.
If you just want to chuck clouds, go buy a a mod that can go to 150+ watts, a TFV4, get the quad coils, and break them in around 50 watts and then slowly work your way up to 90-120 watts. It takes all the guesswork out of it. Plus, with a 4.5ml capacity, it will run for a decent chunk of time before you need to refill(again, I get about an hour of drive time while I vape pretty heavily).