Packs are too subjective to the end user to get a solid recommendation especially form the interweb.
The Hide favors MR, nothing wrong with that but there are better out there but again, better means what to whom.
I have a couple Eberlestock, used for what I would expect you would too. They are heavy, don't carry weight comfortable but get the job done. I like the gun sleeve as an option to tote a gun. Easy entry as the front panel zips completely open, no digging around to find anything. I have a scabbard on one of mine to tote 2 guns. I have used mine to shoot off us as a rest / support. I like the fact its a backpack with carry handles on the side to tote as a suitcase. While I am not into matches, I did take one to Mammoth many moons ago.
Most of the 3 day assault packs, its a clam shell design with a zip top open do not open wide enough to see down inside and you have to dig around to find what you need. The pack design is from Lowe Alpine back in the early 80s and for reason has been adopted as an assault pack. Updated version would be a medic / trauma pack that zips wide open with pockets for organizing small kit. Tactical Tailor makes a quality medic and 3 day for under 3 bills. Yes I had an original Lowe Alpine and have one from todays copy. To use as a shooting support, use a piece a 5mil sheet plastic cut to the inside dimension of your 3 day, run duct tape around the edges for duct tape storage and to protect from abrasion. This will stiffen up the pack in general for increased carry comfort and allow to shoot from the pack standing on the long edge and short edge without collapsing on its self, rigid support.
good luck
