As a fellow PRS fan based in the UK, I too was disappointed with the UK prices. Whether its the UK tax system or PRS responsible for the upcharge, I would rather save the extra for a 'proper' Custom 24.
From what I've seen, the tops on the S2 don't look great (both the figuring and the carve) and I'm not thrilled that for £600 more than the SE model, you still get the SE trem/bridge. Some of the other upgrades like nut and tuners, equivalent quality can be had fairly cheaply.
The good news for PRS however is that I will be making a purchase from them, it just might take longer for me to raise the money for the core model.
Finally, I love the Mira, but again I think they are overpriced here in the UK. I will get one eventually, but I'll wait for them to hit the used market where they will be better value.