Currently using Smok x mini with the Atlantis v1 tank (1.0 ohm coil) and a samsung 25r battery. Getting pretty nice clouds and decent flavor at 40-50w using 70/30 3mg liquid but starts to lose flavor after 45+ watts. If I use the 0.5 ohm coils or different battery will I get better cloud/taste off my tank?
That's a difficult question to answer. There's a reason why manufacturers offer different resistance coils, as different consumers' preferences differ. Some folks like lower ohm coils, some like higher ohm coils. You may not learn which resistance you prefer until you experiment a little with different coil resistances.
Quick question: You didn't say if you've changed the original coil in the tank. Factory-made coils generally have a life expectancy of only 2 - 4 weeks. As a coil is used over time, the flavor and vapor production will degrade; hense the coils should be changed at that time.
Some tanks and mods work well together, others do not. Again, experimentation is in order. Also, there is a good reason why there are so many different tanks, coil configurations, and mods available to consumers. There is no one device which will suit the needs of everyone.
In closing, the power setting (wattage) you use is basically the setting that YOU prefer. Some people vape at under 10 watts, some people vape at 80 watts or more. I generally vape at 30 watts. Most coil manufacturers provide the recommended power ranges for their coils, either on the packaging or on their website.