I have a much, much older version of this fleece that has been sorely abused. It's riddled with burn holes from campfires, abraded from climbing chimneys, stained with tree sap and is still going strong. That bodes well for the new TKA Glacier, which is much softer and more comfortable and somehow also warmer even though the fleece is the same weight. It's a no-frills design that keeps you plenty warm and the one-quarter zip saves weight.
Unfortunately, the older one I have seems to have been better constructed. The new TKA showed up with loose threads in a few spots. While this may not signal bad seams, it does indicate quality control issues. Like most of what The North Face puts out, this one has no recycled materials in it (email and bug them about it if you're into the eco scene). One of the reasons my other fleece is so beat is the fit — it's not as close as I'd like to see in a base layer and so gets snagged on stuff sometimes.
If you like to keep the pace up, the TKA will work as a top layer if it's dry and not too windy. For lift-access skiing, alpine climbing, wet or windy conditions or deeper cold, add a shell and you're golden. Much below 20 degrees and you're going to want a Patagonia R2 even if you're moving.
On a still, ten-degree day skinning into the backcountry I was warm enough with a T-shirt under this until I stopped moving. At the top where the wind scours the ridge, I threw a down jacket over the fleece. Then, when it was time to drop, I ditched the down and threw on a softshell. Perfect. The heavier fleeces would have been too sweaty on the way up and actually made me colder when I stopped.
For 50 bucks, this is definitely a worthwhile investment. If you're into fast and light, efficient layering and who cares about après-whatever, get a TKA. One caveat: if you're into looking good around town, lounging and hanging out, better to get a heavier fleece and pay the extra.