I think, as usual, a lot of Reg readers are missing the point of what DCPWPCW stores exist for.
They're not for _us_. They're not for people who research and make an informed decision. They're for people who "just want a phone" (/cooker/TV/laptop/vacuum cleaner) and want to park outside a shop and take it home that day. The sales force are trained with phrases that enforce the immediacy of purchase, emphasising what's in stock because what sort of cretin would want to wait ONE WHOLE DAY for something to be delivered (for cheaper).
Phones4U were widely (and rightly) critisised for their pressure selling. Go in on a Friday and if they weren't on target for the week you could probably walk away with a new contract, free phone, and £300 quid in your pocket. I speak from experience. Now since P4U guys were absorbed into Dixons (something like 80% of store-in-store staff remained, just with a different shirt on) the culture continues and it's toxic.
Weirdly, if you walk in and show a bit of knowledge, you get left alone. Try asking "So does this device does USB-OTG, and which 4G bands can I use it on if I take it abroad?" and watch as they scamper off to serve someone a Moto G5 with case, screen protector, insurance, memory card, selfie stick and a cuddly toy. I'll say it again - we are not target market.
Plus points of Carphone - they sell open market, unlocked devices. That's it. So unless you get a decent deal on a SIM-free device, there's no sense in signing up to a contract with them. The hipster MVNOs like Smarty and giffgaff offer better value, and network stores like O2 offer better support and range of tariffs.
Anonymous because my insights might just have been gained from working in store until very recently.