I have just acquired the last of the set that I didn't have (the A1). It's an odd set, to be honest, and is basically what Hornby already had tooling for, and what ran in apple green. The obvious omission is the V2, which has been the preserve of Bachmann for years, and including both an A1 and A3 is a bit silly, as the main visual differences are restricted to the tender, dome, and the ejector pipe (A1 is RHD, A3 is LHD).
The models themselves are 75% superb, the lame duck being the P2, which was from the "design stupid" period and is noticeably more basic. The finish on all four is great and they run well enough, although the P2 is a bit less smooth due to its cheapo mechanism.
The main problem with this gloss-finish set is that it makes my NRM Mallard look as if someone has painted it in Farrow & Ball matt emulsion. Manufacturers are generally drifting towards more shiny satin finishes but Hornby still have some seriously flat paint in their range.