1.8 is generally a more intense experience (in a good way, if you're into it - I am) but there are some caveats. Like Kaezziel said, it will drain the battery a bit more quickly.
If it's the clearo with the dangling wicks, they'll also want to burn more easily with 1.8s. They don't wick super well to begin with, and 1.8 ohms will dry the wicks more quickly than 2.4. Probably not the best to chain vape, unless you keep the tank pretty full and move the tank around to help the wicks out.