I eventually chose a "best of both worlds" T400s for my new laptop. It's a lot lighter than my old T60: 1.77kg vs. 2.5kg (the T60 has a 9-cell battery).
Upgrading from the T60, most things on this computer immediately feel right. The tightly-spaced keyboard has a slightly different/soft feel, but is very similar in size and layout. The bigger ESC and Delete keys are spot on. I'm not exactly thrilled about the wide-screen display since going from 1400x1050 on the T60 to this one which is 1440x900 is actually a slight reduction in pixel-count. The display doesn't feel small though, and Windows 7's new-style taskbar saves a bit of space compared to XP. The wide-screen format means there's room for speakers on both sides of the keyboard. I'll be using a 24" Samsung screen via the Series 3 Mini Dock at the office 🙂
The red stripes are back! Yay! The touch pad is textured, but doesn't feel very different in use. Right of the volume controls there's a new microphone-mute button (useful?). Compared to the T60 which had a row of lights below the screen the T400s puts the lights in slightly different places: the central on/off button is illuminated, the caps-lock key has a light of its own, the num-lock light is gone, and the battery as well as the sleep-symbol are only visible on the outside of the machine.
Here are a few pics of the sides of the machine showing the ports:
The front has only the clasp for the screen, which now is on the keyboard side and doesn't lift up like on the T60. Seems to work just fine this way too. The top edge of the screen curves inward to match the rounded wrist-rest on the front of the machine. On the top edge the ThinkLight is now accompanied by a webcam. On the right there's a small WiFi switch and the optical drive. I had a bay-battery for the T60, but although the form of the CD/Bay is the same, the connectors on the back have changed and the T60 battery can't be used on the T400s. There are no USB ports on the right of the machine. On the back there's power-input (Lenovo didn't change the connector or spec, so old powersupplies still work), VGA-out, Ethernet, one normal USB-port, one combined eSATA/USB port, and a DisplayPort. On the left side there's one more USB port for a total of three, an audio jack, and a card-reader.
It's too early to say, but I have a feeling that I will miss the two USB-ports on the right side of the T60. They're now at the back where it's a lot harder to reach to connect a memory-stick or a mouse. Optical drives are probably going the way of the DoDo. The only use I find for the DVD-drive is when installing the Operating System. I've used the drive twice, once when installing Windows 7 and once for Ubuntu 9.10. Better put a battery in the bay to boost the mobile-hours. The card-reader is great! As I've now moved to a Canon 500D camera it uses SD-cards which fit this card reader and there's no need to use Compact Flash anymore. Like the Canon, this card reader operates like a ball-point pen: press once to insert the card, press another time to remove it. Smart and easy, no buttons or levers.
I'm glad the modem is gone!(who has used a modem in the last 5 years anyway?). For roaming the interwebs the machine provides RJ45 Ethernet, WiFi, and a built-in 3G mobile phone. The 3G card also comes with GPS which I have yet to test. No doubt a three-way C405x vs. N95 vs. T400s GPS-shootout is called for!
The hard-drive is a 128GB SSD. Highly recommended although I will have to keep a 500GB usb hard-drive in the bag for larger archives and backups.
After three days of use I'm pretty sure I'll be happy using this laptop for the about next three years. That's how long the Lenovo warranty is, and also how long I stuck around with the T60.