I only have a low level Sniper, level 18, but line of sight can really blow. I was playing in one WZ and I was getting LoS a lot. Very frustrating. So I decided to level another alt :-). But they also have some great advantages. But man, all my heavy hitters were long cast times. One time a guy was playing Peek-a-boo with me. He was behind a pillar and he knew I was loading up my shot and at the perfect time, back behind the Pillar :-).