You asked for preferences and that's what you got.
Colerain is fine it's just that you didn't see a lot of straight barrels out of them when Green Mountain was making them and they offered nothing over Green Moutain unless you were ordering one with radius (round bottom) rifling.
Some complain about Colerain's breeching but the straights don't come breeched anyway, from Rice or Green Mountain either, though Rice and Colerain will both do it for a fee.
Some complain that Colerain's exterior finish isn't as nice as Rice's but I have a Rice that is is rough as any Colerain I've seen and Green Mountain barrels are hit and miss and Colerain barrels file like butter.
Some have also reported that they had Colerain barrels with tight and loose spots in the bore. I have not experienced this and I've never heard of a problem that was brought to them that they didn't make right.
I own several Colerains and have not had these problems and you can't really go wrong with any of these companies. All are known to produce accurate, well made barrels.
Enjoy, J.D.