Perfect for work, great for home

I purchased my Dell Lattitude D620 almost six months ago, and shortly after that started deploying them at work. Overall, I had previously used a Dell Inspiron 600M (the home-equivalent of the Lattitude D600), and moved to the D620 after reading about all of the improvements that they made.

New Selling points:
-Magnesium alloy casing
-Steel hinges (much improved over past designs)
-Improved trackpoint (it's blue!)
-Widescreen LCD
-Core Duo CPU (recently updated to Core 2 Duo)
-Slick black/silver color scheme

Lattitude selling points:
-Improved warranty support (3-year next-day)
-Removeable media-bay (battery/floppy/optical)
-Universal compatibility with Dell D-series docks and A/C adapters

Drawbacks:
-One speaker (no stereo)
-Limited to 1440x900 resolution
-Only choices for video card are Integrated Intel, and nVidia Quadro - no powerful DirectX options
-Not quite as good on battery as the D600/600M

Overall it's a very good notebook. The speed is faster by leaps and bounds over the older Pentium Ms, and the battery life doesn't suffer very much. I'm big on battery life though, so even the slightest decrease bothers me. However, because this is a dual-core CPU, it is still rather amazing that they were able to get this kind of battery life. The screen is just about right, although I would still prefer a higher resolution screen; the older Lattitude notebooks offered pretty absurd resolutions at around 1920x1200, and though that's MUCH too high, I would appreciate something a little higher than 1440x900.

On the note of screens, I would have liked to have more options for video cards than the craptastic Intel integrated video card, and the workstation/OpenGL-based nVidia Quadro. Even though they're both more than enough for office work, and even for an engineer, it doesn't really play very well with any games. Of course, this is a business-class notebook and doesn't technically need anything more, I would still like to have the option available.

Big kudos to Dell on the improvement of their input devices! They keyboard feels more stiff than ever, which is a good thing. The older notebooks had a habit of flexing, which caused the trackpoint to move and make the cursor go flying uncontrolably. The trackpoint has also been redesigned; instead of having a rough easer-head of the older Lattitudes, they've moved on to a soft, concave trackpoint. It actually feels really, really good to use, especially when compared to the older style.

The Dx20 series also brings in a few new improvements. First, there's the option for a fingerprint reader. Pretty handy if you're a stickler for security, although if you happen to get something on the reader or your finger, you might have some problems getting at your data. The Dx20 series also have a different interface for the wireless LAN device; instead of using the tried and true mini-PCI, it has moved on to a mini-PCIexpress interface. Not a big problem if you're using it as-is, but I upgrade my wireless card to function with my 108mb/s wireless network at home.

Overall, it's a very good notebook. There are some big improvements over the older tech, but at the end of the day, unless you need a faster notebook, you won't see any BIG improvements. Of course, it's always good to have the latest and greatest!

**Update**
After trying out Vista, and reinstalling XP, my D620 failed to see the bluetooth adapter.. at all. After removing, reinstalling, trying drivers, etc etc, I decided it was time to throw in the towel and get a replacement module from Dell. My call was answered quickly, and by a human being! He ran through some quick troubleshooting, then had me run a utility that allowed him to remote in and confirm that it was missing. In about ten minutes, he had a replacement module sent mailed to me next-day. Overall, I was very happy; the rep could've been a little nicer (he wasn't exactly a polite guy), but he got me taken care of very quickly without any run-around. I popped in the module the next day, mailed the defective unit back in their pre-paid box, and I was good to go!

***Update 3/30/08***
I've recently sold my D620 (and moved to the D630) and thought I would add some final thoughts.

First, the battery lifespan (not to be confused with the charge) is rather poor. In under a year, the power that the primary battery provided has gone down by approximately 50%. I understand that batteries do become weaker over time, but this is a rather significant reduction in a relatively short period. At work (where we have a number of them deployed, as well as it's 15.4" cousin the D820) I have users asking for new batteries because theirs (the standard 6-cell) are only providing approximately 30 minutes of runtime. Even the D820 I use at work is reporting a battery that has reached it's end of life, after a little more than a year.

Depending on your usage, the size is very, very good. For a desk, I would suggest a 15.4" panel, and for heavy travel I would suggest a 12" panel, but for my usage (around 30% travel 70% desk), the 14.4" panel is very good. It's large enough to accomodate normal tasks (especially with the better 1440x900 resolution), but not so small that I have trouble with things. In restaurants I wouldn't mind something a bit smaller to work on while on the go, but it's not too bad.

Get a D-dock. Really, pluging and unplugging various connectors (power, LAN, speakers, mouse, printer(s), etc) gets to be quite a hassle, and having the single point of contact in the dock connector is really great. They're available pretty cheap (less than $40 on eBay), and not only save the trouble of disconnecting and reconnecting everything, but also save the ports and the cables themselves.

Update 4/2/09:
I've since sold this notebook, but having serviced many of them at work I can say one thing about this series: the batteries die.  Prematurely.  I don't know anyone who had a DX20 series notebook which has a battery that has lasted, and even though I sold my D620 the new owner relayed that it's battery has also begun to fail.  I don't know why, and I'd be suprised if there was anything to substantiate it, but it seems to me that they did something to them becuase that was when the "exploding battery" scandal hit the news.