I have no problem with it, I'm a normal guy that keeps his nails well clipped. Takes like a second to gently open it, doesn't bother me at all, I have a Ringke Slim Dot case and no problem with it there either. Well worth it for the water/dust protection imo. If it bothers you just rip it off, but you'll lose that protection. My S2 died in water so to me it's worth the 1 second hassle lol
Plus I'm getting about 2 days with heavy use and hours and hours of on screen time, ridiculous battery life, far better then my S2 rooted and running the best rom for battery life. So it's not like I have to open the flap multiple times a day.