Interesting pic, regarding formation flying.
Still. it would be interesting to try it out. <G>
Yes Vatsim does suffer, but I haven't seen it as bad as Gerry was describing earlier where someone had logged off before another saw him land. I have been doing some formation flying lately - two Tiger Moths really close together. Once apon a time this was impossible on Vatsim, as the leader danced all over the sky, but nowadays you can formate up to about 100 yards apart quite successfully. Squawkbox 3 has a "Formation" mode - no idea how it works - which makes even smoother formating possible, and we are hoping (we aren't very good at it yet) to get to the point where you can see the tread pattern on the lead aircraft's tyres!!
There is a picture here.