As you increase the vaporization temperature past certain thresholds the various terpenoids found in cannabis are released. This is why your vapor will taste different when vaped at 350° than it does at 385°. My recommendation is to experiment yourself to find what temps suit you best. Start out low and slowly increase the temperature until you reach your desired level of strength and flavor.
Once you go over roughly 400°F you'll probably start to get an unpleasant taste from your herbs, and once you hit 445°F you're at the point of combustion, so it's recommended to refrain from raising your vaporizer's temp past that point.
The Herbalizer is one of the more recent models I've reviewed and it's pretty unique because it utilizes a halogen bulb heating element that produces excellent vapor at a wide range of temperatures. This is basically the best vape for experimenting with different temps to see what effects you like best, because vaping at 330°F will provide a very different experience than vaping at 420°F, and actually the effects will slightly change every 10°F you go up.
The Volcano Vaporizer (one of my all-time faves) is best set at about 6 on the dial, or roughly 374°F (190°C). When you factor in the temp flux of the heating element (+/- 9°F) your actual vape temps will be between 365°-383°F (185°-195°C) as it cycles on and off. The digital model is slightly more precise with a flux of only 2.7°F. Lately I've been experimenting with increasing the temperature past 6 after the first balloon, but it's all personal preference so see what works best for you.
The Extreme-Q seems to work well set between 383°-392°F. Because of the way this vape is designed the temp up where the herbs actually get vaped will be slightly lower than the core heater temp. I guesstimate the true vape temp to be roughly 20 degrees lower which brings you down into the ideal vape zone.
On the other hand, the Vapir NO2 is the opposite and in my opinion runs hot, so I've found the ideal temp setting to be between 350°-355°F. If you put it any higher than that you might overheat your herbs and get a burnt/funky taste.
The Magic-Flight Launch Box doesn't have a heat setting so you need to determine how long to keep the batteries engaged yourself. Taking small, quick draws is usually the most efficient way to use this vape and this method helps keep the temp from getting too high inside the chamber.