Looks like we are going to have to agree to disagree here. I think Coleman would be a huge upgrade over what we currently have and I feel he would further improve. His performances over the past 3 seasons have been very solid and he was brilliant in 13/14. Again, I reiterate, in my opinion, he was better than Rafael in 12/13.
It appears that you class him as mediocre because of the club that he's coming from. Plenty of our signings over the years have been from far lesser clubs. He would take time to adapt to a new club like any player would, but I believe he would go on to be a good solid signing. Is Carvajal that much better? I haven't seem anything to indicate that he's flights above Coleman. What I see is a player at a far better club that naturally will look better. Everyone spunks over names like Fabinho; but how many, hand on heart have seen him play consistently? People like to jump on bandwagons with these foreign players. Darmian seems a good player and
@izec gave a good summary of him yesterday but I'm honestly yet to see him play.
As for Azpi, I feel you are wildly overrating him. I would have Coleman as comfortably better. Azpi is a typical Mourinho player that has been moulded into an extremely solid fullback. He's excellent defensively but is seriously questionable in an offensive sense. I'm stunned you think he's such a complete fullback that you have him in the top 5 in the world. I wouldn't have him anywhere near it.
Anyhow, it's all subjective and we aren't going to agree so no point continuing this debate really. Fwiw, I don't see us going for Coleman. We get linked every summer and still nothing has ever remotely materialised.