Mark DI would read this website, it seems that Revell and Airfix both have their things to adjust/refine, both need some work to get it right, but when comparing the most visible parts, Airfix should build a little bit better ( I've bought the Airfix kit, just based on this site and some info on lakecountyspaceport.)
spaceinminiature.com/ref/sts/sts_table.html 2 17 January, 23:18