Are the sights removable on all SW 15-22's??

Yes, all are removable.

Yeah most people replace the stock iron sights with Magpul MBUS flip up sights. What's cool is you can buy them in black, olive drab, foliage green or desert tan. They give you any color option you plan on going with your 15-22 build.

I'm personally doing an Olive Drab build. I'll be posting pics soon.

Good luck!