I've only had mine since Wednesday so am still finding out its perks but so far the only real gripe I have is the hard disk.
The 5400rpm drive really really lets the machine down IMO. Installing Windows 7 SP1 last night and the machine was unusable for about 30 minutes with the HDD light on solid for that time. I'm sure the Dell wasn't as slow as that.
I do miss the firewire port and dual HDD bays that my old Dell had but I did discover that the Asus had bluetooth which was a bonus. The Bang & Olufsen speakers (I have no idea why B&O would put their name to some laptop speakers) are pretty good for speech and special effects but pretty sucky for music, even with the external 'subwoofer'. Not a huge issue for me as I have the laptop connected to a hi-fi amp but I expected better.
Overall though, apart from the slow hard disk, I'm very happy. The screen is excellent, the keyboard feels nice to use and the laptop overall feels pretty well built.
I've got to agree though, I couldn't find much with this spec for the money. Before I settled for this machine, I was looking at another Asus laptop with a Gen2 i7, 8GB RAM, 750gb 7200rpm HDD, GT550M and 1080p display for £850.
Sadly the shop was unable to secure any stock but IMO, that was one hell of a spec for the money. I paid £700 for this which seemed like good value.