I've had two fairly close encounters both with gliders in my 300 odd hours.
I also fly as high as I can and choose odd levels eg 2200 ft or 1900 ft in the crowded SE where TMA is down to 2500 and many seem to pick 2000 or 2400.
One interesting observation from an IMC holder, flying North about 500ft above a thin layer of Stratus with a RIS I got a lot of opposite direction traffic info and never saw any despite a careful look out for it (and pop up traffic). I can only assume it was below the layer and I was above. It's safer on top
