It's not really ideal for a long through hike though. By backpack standards it's heavy. And it comes from an age before ergonomic considerations were made for the guy who had to wear the pack. The waist support is somewhat rudimentary, and I didn't even figure out that it HAD waist support until I'd owned it for a few years. The webbing belt is just a little bit too short for me to wear comfortably, but it might work better for someone else. Due to its age, it pre-dates the MOLLE attachment standards, so there's a whole world of attachments that a newer military pack can take advantage of, but the ALICE misses out on.
It's nice and big though. Real big. And covered with pockets, thus lessening the need for those attachments. And these pockets are quite generous in size, I can fit my whole BioLite stove into one of them. That means it'll also take a good sized nalgene bottle or similar device. The interior is only divided into two different compartments though, an upper interior pouch and and the roomy main compartment. The Large Bag is probably capable of carrying way more equipment than you need or is good for your back, though you may want to pack it in compression sacks or gear bags to better segment and protect your load. The Medium bag is really more like a small bag with good PR, and I highly recommend seeking out the large bag instead. The main compartment closes with a drawstring, and then a flap covers the drawn aperture. Despite not being a MOLLE compatible bag, there's plenty of room to attach to the frame or bag with gear ties or similar.
The big reason I'm loathe to use mine is that my back and the frame don't quite agree right. One of the supports presses into me in a way that just isn't something I'd want to deal with while hiking for 20 miles in a day. Its great though, if I only have to go for 20 minutes to an hour, or if I need the storage capacity. And for the price, it's pretty nice. a MOLLE II bag or ILBE, more modern bags (themselves rough and tumble cousins of the modern hiker's bag) run over twice what I paid for the Alice. That said, $100-150 is cheap next to some hiking packs, and certainly a worthwhile consideration for someone who wants to get outfitted without paying REI prices.
Would I recommend it? For certain situations I would. If you need a bag to get from X, to Y and stay there, it's good. If you need a big bag, cheap, I would. If you're a masochist and don't want a more ergonomic bag, it'll do. It's not ideal for backpacking though. If you need a backpack that you can drag through hell, it'll answer the call.