The REI Flash 45 is one of the most affordable packs we tested, but it unfortunately performed so poorly we have a hard time recommending it over much higher performing competitors. The weight-to-volume ratio is poor and the very flexible simple frame does a poor job transferring weight to the waist belt. On the plus side, it is cheap.
The Flash competes most closely in volume and features with the three highest scoring overall models. The Editors' Choice Gossamer Gear Gorilla and the Best Buy Osprey Exos 48 are both much better packs.