Ah so arfv3 isn't necessarily better than v2? Gets us buying more watches I guess.
That happens too - sometimes there's a desirable earlier version because for some inexplicable reason the factory changes something that was perfect the last time and not so good in the latest version.
But generally, the current version of any model by each factory is what you need to compare and choose between - these will be the only ones you'll get from the TDs anyway.
As you get more knowledge, become more watch geeky and more of a PITA to live with, you can start to monitor the M2M sales threads for that elusive out-of-production special version, or... a Franken!