The 127 will be very good , as todays achros are all very good , with the coating technology and computer designed and polished lenses.
I have a 150mm Skywatcher f/5 here in OZ ( My chromocored f/8 is still in NZ ) and even at f/5 its super sharp and shows heaps of deatail on jupiter , with some CA , not to bad , but there of course .
If its to bad for some people I use the 100mm hole in the lense cap to turn it into a 100mm f/7.5 and the CA almost dissapares .
But CA does not worry me to much , as every ones tollerance is differant.
Brian.