ConCor - so so, some excellent, some not very good at all. A larger percentage of ConCor’s HO product was picked up from others when they discontinued it. With the wide variety of product sources, no concrete statement is possible. More often than not, it is not state of the art.
Roundhouse some is very good, some is very old and not up to present detail standards.
I have just purchased 2 Walthers Cabeese (at $40+ each) and they are the worst running untis I have straight out of the box. If the rest of their range is anything like these over priced babies… I would be checking them out first.
I have three of the newer Walthers C-30 SP wood cabooses. The trucks are terrible and often derail over points etc (way too much slop in the sideframes). However, the detail and finish of these cabooses is quite good. For many of us the only other option is brass or the AMB kits (don’t get me started). Change out the trucks and you might be a happier camper. I think that it is shameful that models aspiring to this level of detail come with these trucks.
Be aware that manufactures change their product lines. Some China made Athearn R-T-R with plastic wheel sets wont take the same wheel sets as the Athearn BB. New Athearn R-T-R comes with metal wheel sets. This example is not to scare you off but to give you a heads up that you wont nail them all.