What about the Galloway Away mission?
That was pure torture!
I didn't say Galloway Away was so easy, I did it a lot of times to complete it, but what I'm saying is: If you compare any Bully mission with GTA missions, you'll find Bully is very easy. I played 5 GTA games (III, VC, SA, LCS, VCS) before playing Bully. That's why it was too easy for me.
Also, btw, Finding Johnny Vincent was a lot harder than Galloway Away for me.