I've used this pack for day trips and filled it FULL. I use it for split boarding so put my telescopic poles in the horizontal ski carry. It works acceptably well. It has also held my board in split mode (roughly same size as 2 extra fat powder skis)
The shovel it comes with seems very small but when worrying about carrying extra grams you have to stay small. The probe is excellent, top of the line. the bottom of the bag tapers to a very narrow point which is not depicted well in the stock photo. It has a whistle on the chest but it's not that good so I strongly recommend not relying on it and getting a nice one for the chest pocket.
In the summer I remove the avalung and use it for hiking in BC. It was quite easy to get out my first try. It took about 5 minutes to figure out. I'm sure it would only take 1 minute from now on.
I feel like the best use for this bag would be to pack it into a multi day bag and then pull it out when climbing above camp, leaving your multi day bag and unneeded equipment at camp.