I'll echo pretty much everything Steven Komae said in his earlier post. That's all good advice.
Michael, I think your ideal torso setting for that pack is between a medium and a large. I feel silly for even asking, but you do know that you can set the torso wherever you want within its range right? It doesn't need to be on the "large" or the "medium" indication, those are just arbitrary. I'm sure you already know this though.
Anyway, I have that Osprey 60 pack as well, and I find it to be very comfortable and easy to get a custom fit, so I'm sorry to hear you're having a harder time.
A few things to consider…
Make sure the load lifter straps travel under the small keeper straps on top of each shoulder strap. This will ensure that the angle with which the load lifters are pulling on the shoulder straps is always ideal. If it's not currently in this configuration, you might give that a try.
When I initially fitted my own pack to my body, I first set the hip belt to where it was perfectly hugging my iliac crest, then I went to town on the torso length. I would move the torso up and down by fractions of an inch until it was just perfect for me. I find that even being 1/4" off can lead to a much less comfortable carry, so I'd advise really playing around with the sizing until you get it tweaked just perfectly.
From where I have it currently set, my shoulder straps come over the top of my shoulders, then travel down maybe an inch or so before meeting the pack. This setting allows the load to feel very secure laterally, while also allowing me to place about 80% of the load on my hips (this is how I like it). Imagine setting the torso to where it's slightly too small, and you can't get the weight on your hips, then raise that up just a bit to where your hip belt can bear the weight but where the shoulder straps are still hugging you.
Again, my best advice is to just keep playing with this torso length adjustment until it feels perfect. It might take many tries. If you just can't get it to feel comfortable, then it may just be that this is not the pack for you. Most packs that I try on I do not consider comfortable, and I assume it's as hit or miss with everyone else as well.
Good luck!
