I think the same. Hence the question here:
http://www.pprune.org/tech-log/58081...ml#post9422235
The present base have average taxi out times 15 minutes, 10 more when busy. I am slowly leaning towards trying one day... but exactly as you point out, would already start the 2nd when 3 to depart and 2 more to land, i.e. approx 7 minutes to go.