It's hard to beat that price ($79.99)! There are some comments on-line about the roughness of the fabric and the quality of the workmanship but it is also rated as a Best Bargain by the same reviewers. The 55L capacity is a good size for smaller scouts. However, if they grow a lot during their teenage years they may need to upgrade (to something in the $84.99 Explorer 65L, the $122.14 Ultralite Mountain Adventurer 65L, or the larger adult sized $99.99 Fox 75-85L size). You don't want to consider anything smaller than a 45L capacity (the $119.99 Ultralight Talus size). From the picture it also looks like the pack has loops on the outside to attach bulkier gear such as sleeping pads, sleeping bags, or tents. The ability to strap stuff to the outside of a pack is vital. This does mean that you need to invest in accessory straps but these are a low cost item.
The big thing (and if buying online you cannot tell) is how it fits. All packs are adjustable to different heights and body types. There are also little cheats that can be done to accommodate pre-pubescent builds such as "grafting" on foam rubber to the waist belt to create artificial hips. But the only way to tell if it's a good pack is to put it on, adjust it to your frame, put some weight in it (about 1/3rd body weight) and walk around to see how it feels. If the return process is easy like I think this is (it is super simple with Amazon) it is a great starter pack. Most of the comparable ones for children/smaller framed adults start in the $160+ range. This wouldn't be my first choice for the Appalachian Trail but it seems more than fine for Scouting trips and treks. And again, the price is awesome. At that price point you free up funds for a better quality sleeping bag and/or tent which is were you really want to spend for quality.
Hope this helps. I am always willing (and borderline obsessive) to talk about gear.