For what it's worth, REI's house-brand items are usually comparable in quality/performance of the mid-upper range, especially in their backpacks which (while not exactly Gregory or Osprey) get rave reviews. The REI tents are frequent items you see along the trails and the people are happy to say they last a few years. The bonus? They are usually priced closer to Kelty/Eureka than Big Agnes or Mountain Hardware. Good stuff.

I haven't used Sierra Designs myself so I can't comment on them. (Rare thing but if I don't have first hand experience I don't offer recommendations most of the time)