I agree with all the above. Biplanes do have a poor glide ratio compared to monoplanes, that is, biplanes loose altitude faster. Biplanes also present a more confusing visual image in the air. Most pilots find it easier to lose orientation when flying a biplane. Biplanes also tend to be less stable than monoplanes. I have a Tiger 2 that tracks like it is on rails. and almost flies itself. I have a GP Ultimate Bipe 40 that requires I stay on top of it every second.

Dead sticks in a biplane are no problem once you get used to them, you just need to maintain airspeed by keeping the nose down.