Guides are warmer/thicker. Chinooks are in between and have knee pads. Attacks thinnest/coolest out of the three. Guides are really only for late season/cold temperatures. The other two are pretty versatile. You can wear them into the late season and early(ish) season. Although the Chinook might be a little more mid season to late season. A little warm for early season imo, depending on where you're at.