I just called HDEWCameras and had a lovely chat with them.This is what they told me:
1) All their cameras are shipped to UK specs BUT come from outside the UK, ie they have UK cables for charger.
2) UK Canon honour their 12 month warranty on their receipt. After the first 12 months the camera goes to their UK Canon repairers under their further 2 year warranty. (The camera comes with a 3 year warranty from new)
3) If you want a VAT receipt you have to ask for it at the time of purchase.
4) They hold no stock on their premises because the cameras are shipped from outside the UK, so items are delivered after order is placed and currently they are saying 3-5 working days to deliver.
5) They ship exactly the same boxed cameras as any Canon supplier, - all these cameras come out of the same factory, so there is no difference in what I would get from them as to what I would get from say John Lewis.
6) They are not eligible for the current Cashback offer from Canon, but their prices are at least £200 cheaper than one would get even after the cashback, and one gets a 3 year warranty and a free 4gb memory card.
I am not posting this to "plug" HDEW cameras but just to provide some information given the other feedback posts above. I am still undecided about which way to go, I still like the John Lewis offer as it includes a 2 year warranty, for an extra £35 one can upgrade to a 3 year warranty - this is eligible for the cashback promotion.
Off to think it over over a cuppa!