I don't know about better service. I've not had enough personal dealings with Comet in the UK to judge their particular quality of service, but it's almost always a given that service in a proper brick-and-mortar store will be head and shoulders above most online stores. I never buy any kind of hardware online nowadays. The hassle with dealing with faulty goods goes far beyond the savings of a few euros/quid from buying online.

That being said, most shop assistants in franchise hardware stores here in Germany and over in the UK are thick as shit and are just instructed to sell you the most expensive product possible, with the exception of our local Saturn, where they do seem to know their stuff. I went into Dixons in the UK a couple of years ago with the aim of spontaneously buying a Wii that was on offer, but I wanted to know whether it used a standardised mains cable that could be swapped out for one with a Schuko plug. They couldn't tell me and were apparently completely unwilling and unable to find out.

Personally, I prefer the smaller independent stores. The people who run them usually take a lot more interest in their work.