I've read and heard about a lot of people not liking the new launcher and after I figured out the optimal way to use it I like it. It's easier to switch characters than ever before. Let me show you how.
1) Open the launcher and click the Auto Play checkbox in the bottom right corner.
2) In the settings on the Start Up tab, make sure you uncheck the box for closing Eve Launcher after starting.
3) Log in and it will auto-launch the client. Select your character, start playing.
4) Meanwhile, the launcher is waiting patiently behind the scenes for you.
5) If you want to be another character on the same account, just close the client and hit PLAY on the launcher. You are still logged in! If you want to launch a second client, just switch to launcher and click the "Switch Account" link, enter username and password and hit enter and BOOM! New client launches.