I've watched videos of rabbits running up to snares on fencelines, avoiding them, jumping under them, through them... pegandgun had some good footage, showing this on the dales..
Winter when rabbits are more active at night and the days are shorter its less of an issue, as the spring and summer come into play and there more active during daylight, is when it can affect you... smaller juvenile rabbits, visibility, etc .. obviously you still snare a lot, but I find you can get more knocks during these periods..
I've used new shiny fence snares on many occasions but I still prefer a weather