The major caveats on the Envy are that it has serious, deep issues preventing Linux from running on it, and it has no displayport or dvi out for driving a 30" monitor.
The Dell's biggest weakness is battery life.
- Touchpad click buttons don't work, forcing you to double-tap to click
- Weird BIOS caused both TurboBoost (the Intel extension that powers down cores and speeds up others) and ACPI to fuck up, leading to no TB and no heat management, fans ran constantly, very bad news
- Buggy sleep/resume
Points 2 and 3 are fixed in 2.6.33+. Point 1 can be fixed via a patch to the synaptics module, but I just use an external mouse all the time anyway.
I believe you can thank this fellow for many of these fixes: http://www.chizang.net/alex/blog/2009/12/21/linux-on-the-hp-...
1. The screen only tilts to ~105-110 degrees. This makes it tough to use on your lap or on a short table (commonly found in coffee shops sadly).
2. The AC-DC power supply is bulky. The plug has 3 pins too. Earth is not needed for laptop power supplies! There is no electric shock risk for a laptop user! I was dismayed to find such a hideous power supply bundled with this laptop.
Still, I bought my Envy about 6 months ago, so I'm not upset (at least that's what I'll tell myself).
(I complained about this to a long-time mac user, and he said "You're probably using it with the display on.")
Although they made it right, that's the last time I'm going to buy a Dell -- particularly one built on the newest tech. I don't think the QA is there.