In reply to Camaderry: It's going to be down to personal preference I guess. The Lowe Alpine is heavier but a bit larger, so if you think you'll be cramming it full and carrying it loaded I guess that makes sense.
If you are carrying it light the Medusa is a great pack, light but tough and seems much larger than the 32 litres suggests.
I personally like the Medusa for scrambling and as a day bag. I use it more than my larger pack and found it comfortable for climbing in. It doesn't move around. The back system isn't very technical, but it's not designed for heavy hauling, just make sure nothing too lumpy is sticking in your back.
Guess it will come down to fit though, as the backs aren't adjustable.