Launchers vs. Stock

I finally made up my mind to buy a Nexus 7. This will be my first pure Android device and I'm a little hesitant about installing a launcher because I have barely any experience with them and I would like some feedback about that.

I had experience with the Go launcher on the S2 (gingerbread with touchwiz was so bad that I had no qualms). I can't buy things on the Play store, so it was a little limited, but you could do so much more with the launchers and it made the device a lot better looking. I don't have a lot of experience with launchers, so some personal stories would be nice.

However, the interface is less polished, there were bloatware and the settings were more confusing. I feel that with the nexus 7 I won't have to worry about fluidity but it might be a different story with launchers.

IMPORTANT QUESTIONS

How do you feel about launchers and what were your personal experience with them?

If I revert back to stock, will all my settings be lost or will it just revert back to before I had the launcher? (If the latter is the case, I'll feel safe with playing around with it)