I've used the Osprey Farpoint Trek 55 on a couple of trips, and it's been pretty solid for me. In terms of comfort, the suspension system is quite supportive. The backpack has an adjustable harness which helps distribute the weight nicely across your shoulders and hips, making it easier to carry heavier loads without too much strain. Another thing I appreciate is the ventilation, which is important when you're on the move for long stretches in potentially warm weather.
In terms of durability, Osprey is known for making robust gear, and this pack is no exception. The fabric is tough enough to withstand some rough handling; I've taken mine through some pretty rugged terrain without any issues. Regarding capacity, it should be sufficient for a week-long trip, especially since you mentioned you pack light. There's also a sleeping bag compartment at the bottom that can help you organize your gear efficiently.
As for weather conditions, it's pretty good at handling a variety of climates. The fabric is water-resistant, which is helpful in light rain, but for heavier downpours, I recommend investing in a rain cover. It comes with an integrated cover that you can deploy quickly, which is a bonus.
If you're looking for alternatives, you might want to check out the Deuter Aircontact or the Gregory Baltoro series. Both are well-regarded for comfort and durability, though they tend to be a bit heavier. Ultimately, the choice depends on what kind of trips you have planned and how much gear you're carrying, but overall, the Farpoint Trek 55 is a great option for many travelers.