My amazing Tak NJP mount, with no Adaptive Optics or even PEC, produces quite incredible performance!
Guiding accuracy is essentially perfect. Four typical guide graphs showing that average guide errors,
across the sky, are around just +/- 0.35 arc sec, both near the celestial equator and far in the south :-)
http://www.pbase.com/strongmanmike2002/image/166437748/original