This is a really good bag. I debated forever on what to get, but finally decided to go this route. I was looking for a day pack, but not something super tiny.
I think the 34 is really a great balance for a good day hike. It can hold quite a bit, but shrinks down nicely when you don't have a full load.
The bladder storage is way better on this than on my old Stratos 40, I'm happy to see that. I don't think you can easily stick one in the vented backpanel like on the Stratos, but I'm must less likely too as putting it in the bag doesn't seem to kill storage like it did on the Stratos.
Inside out compression is cool - I can still stick stuff in the side pockets when I have things compressed well.
The other commenter mentioned weight - yes, don't plan on a heavy load with this. But it does do really well in 20ish pound range. And it feels so good on your back!
If there is anything I'd like to change - I'd really like this more like the Atmos line with more durable straps, slightly more padded belt, etc. I also miss the zippered compartment access on the Stratos 40. But all in all, quite happy.