I went off topic mentioning the irons, lets just keep this focused on the hicor drivers. I was looking for post 2005 hicor models and there are very few available. The big manufacturers stopped making them and only a few small companies make them at 460cc. They may have become more forgiving, but not necessarily longer if they can't hold up to high clubhead speeds. As far as I know, the 2005 models from Yamaha, Srixon, ONOFF don't have speed limits.
And how can I justify the price difference?