The North Face Gritstone Softshell Jacket - Men's - 2010 BCS

In terms of warmth or weather protection - nothing. If you're just looking for a jacket to wear around town, they'll be the same for you. However, the Bionic breathes very poorly and this does an excellent job of allowing out the moisture vapor from your sweat. The hand pockets of the Gritstone are higher up to be harness and backpack compatible, and are larger so you can get into them with big mitts or gloves on. The pockets also vent. The Bionic has no stretch or give, and the Gritstone does. All told the Bionic is a casual only jacket, and the Gritstone will work much better for technical use as well!

Nope!

The fit should be the same, with the exception of the Sentinel Thermal having pre-cinched cuffs and this having cuff tabs. The thermal fleece (theoretically) is about 15-20% warmer, but has a tendency to 'grab' whatever layers you have below it. The Windstopper of the Sentinel has pretty nice give through the shoulders, but the Gritstone isn't lacking in give either. Windstopper is slightly more water resistant, Windbloc is more breathable. The alpine pockets of the Gritstone are easier to get into, and ultimately will help with venting. The shell material of the Windstopper is a touch smoother, making it a bit quieter. All told, I own a Sentinel Thermal from last year (it's better this year), but I would still purchase the Gritstone if I could make the decision again this year. Not to mention that the red zips help it look a little less dull!

Spencer,
The Gritstone Softshell is NOT zip-in compatable, but is an awesome mid-weight softshell.