Ports and Features
The T420s has almost the same selection of ports as the T410s.The only significant change is that the eSATA/USB combo port has been changed to a USB 3.0 port. I would have preferred to have been given both the eSATA and USB 3.0 options. Thus the total port count is two USB 2.0 and one USB 3.0 ports, a VGA port, a LAN port, a DisplayPort socket, a 34mm ExpreessCard socket (with an optional SD card adaptor) and a docking station connector on the base. One of the USB ports can be used for charging portable devices when the computer is off. For me, the port layout is a major step backwards compared to the Dell E6410 which had most of the ports on the sides. Putting the USB ports on the back is an inconvenience, particularly when it is necessary to look into the socket to see which one is blue (USB 3.0) and which one is yellow (can be used for charging).
Back: AC adaptor socket, LAN port, USB 3.0 port, USB 2.0 port (with charging option), DisplayPort, VGA port and fan exhaust. Also, hidden in the battery compartment is a SIM card slot for the optional WWAN module.
Optical Drive and UltraBay
The optical drive is a super-slim 9.5mm (3/8?) thick unit with an SATA connector. I received a Panasonic UJ8A2. It has the full set of DVD burning facilities including burning both +R and -R double-layer discs. The optical drive is one of three options for the UltraBay, the others being a 3 cell battery and a 2.5-inch storage device caddy. (I can confirm that the older caddy P/N 26R9247 and the older battery P/N 43R8890 both work with the T420s and may be easier to source than the newer parts).
My one grievance about the UltraBay is the fiddly release mechanism. Perhaps it’s a deliberate design to encourage users to shut down their computer, but trying to lift up the side of the computer and operate the release mechanism with the computer running is a test of manual dexterity.
Keyboard and Touchpad
ThinkPads are renowned for their good keyboards and the T420s is no exception. The T420s keyboard appears to have the same 7 row layout as its predecessor. It has an extra-large Enter key while the Escape and Delete buttons are double height. The BIOS is Lenovo allows you to swap the function and control keys through software (Lenovo are one of the few notebook manufacturers to have the Fn key in the corner). However, there is no provision to physically swap the keys which are different sizes. The keyboard also offers page forward and page back keys for stepping between web pages (unfortunately this functionality does not work with PDF files).
Above the keyboard are physical volume controls and both speaker and microphone mute buttons. There is also a blue ThinkVantage button. The speakers are on each side of the keyboard. Lenovo have yet to adopt backlit keyboards and provide their ThinkLight (a small LED in the top display bezel which shines towards the keyboard). It doesn?t provide very uniform illumination but its better than nothing.
The T420s uses Lenovo?s UltraNav solution which comprises both the TrackPoint stick and a touchpad. The touchpad is a medium-sized 77mm x 45mm Lenovo branded Synaptics touchpad which supports various multi-touch gestures. The touchpad has a textured surface and is flush with the palmrest. However, the touchpad buttons are relatively small and on the front edge of the chassis.
The TrackPoint is very smooth to operate. I’ve had a tendency to use it with the middle button for scrolling down pages which I find easier to use than the scrolling on the touchpad. There are only three status indicator lights above the keyboard which are: Wireless on, Bluetooth on; and hard disk activity. The CapsLock key includes its own status light.