Some Speculation based on Experience
If you are experienced and know what you want go for it. But if you are not please consider this advice. External frame packs have not been popular for some time. 4.8 pounds is a heavy pack. This pack has some very nice features and would probably last your lifetime, but my guess is that as you gain experience you will understand how critical weight is and will shed this one for one that weighs closer to 3 lbs. rather than close to 5. My JanSport is not identical to this, but the weight is and I will probably never use it again because I now own much lighter packs that are more than adequate for the job.