DMM wrote a review of Patagonia Guide Softshell Jacket - Men's on January 24, 2010
The Patagonia Guide jacket is a great mid-weight softshell. It is neither windproof nor waterproof. However, it is highly water-resistant and keeps out all but heavy winds.
What this jacket does well is allow just enough air to move through the fabric to help sweat evaporate when you are active in cool to cold conditions.
Rain beads up (it has a top-of-the-line DWR); however, the jacket is sewn and is not seam taped, so heavy precipitation will eventually seep through.
The outer fabric is pretty burly. It easily resists abrasions. It also provides plenty of stretch. The inner fabric has a light nap and a soft hand. It feels smooth and warm against the neck.
The pockets are set perfectly for using a pack, plus they are large enough to carry necessary items (e.g., keys & wallet around town, ski skins & a snack while in the back country).
I've found the jacket cozy in 40s and upper 30s with a layer or two underneath, provided that I'm only lightly active. It requires less layering (only an R1 or Capiline layer), if I'm really working up a sweat.
Compared to a jacket with Power Shield fabric, or another non-windproof fabric, I believe this is a better value. That said, jackets like this will all perform similarly, so I recommend going with the cut and design that you like best, at the best price.