My wife has it. It’s a bit bulky as a day pack and doesn’t pack down as small as most. Still works, just a bit bulky with how the top half of the bag compressed and the compartments are made. I wouldn’t count the bag out as a day pack though. It will still work fine. Is this a decision as to one you plan to purchase?
Does it work as a daypack? Absolutely. It's the only backpack I own so I use it as a daypack frequently. It packs down small enough if you empty the main compartment and tighten the straps and just use the lid pockets. Or you could remove the lid altogether and just use the main compartment. It'll never be as small as a true day pack, but to me, it makes more sense than having a dedicated day pack.
Its a great day pack. I had the MR Metcalf and used it on many western hunts, both extended elk/mule deer hunts and day hunting blacktail near my home. It was a great pack but for me, just wasnt comfortable with weight. It would slide off my hips consistently and I needed more lumbar support. I upgraded to a Kifaru and the waist belt/lumbar pad is night and day difference...for me.
It's the only pack I have now, so I use it on all my whitetail hunts, shed hunting, and whatever other hiking I might do. There are better day pack only bags out there, but if you're ever planning to expand into over night trips, or want to use the frame to haul a stand or meat out you won't regret having the Metcalf.
I just bought a MR Metcalf, I also bought the MR Mule so i can swap bags for use as a daypack. they use the same frame. Got it for $125 with 10% off at black ovis(no tax & no shipping) so for $110 and having the ability to still pack out game its a win/win. I also plan on Strapping it to my Metcalf when going out west so I can drop my Metcalf at camp and run my Mule for a day pack with meat hauling capability.
IMO there are two components to consider - frame and bag.
A full size MR (or kifaru or other frame) is going to be somewhat bulky and heavy as a day pack, regardless, but it gives you the ability to haul weight.
Bags come in various sizes and anything over 40L or so is likely more bag than you need for a day pack. Some compress better than others but you are always going to have some slop in that you have to compress.
To get the best of both worlds you really need multiple packs. However, 1 or 2 carefully selected packs can cover most needs.
I run 4 packs depending on the hunt:
-22L daypack for short stroll with no chance to haul meat
-MR pop up 38 for dayhunts where I haul stands or maybe meat
-mr sawtooth for heavy day hunts up to 1-2 nights
-mr beartooth for 1-5 nights
When I hunt with the beartooth, I just use it as a daypack. Carry an extra, smaller pack bag is just too much extra weight for the limited benefit.
So, to your question, does the Metcalf work as a day pack? Yeah. It is fine. If you want to get multiple packs then they will add some function. Adding a mule bag or something else smaller would work a little better for just day trips but it isn’t really necessary.
Final thought, if I only had one pack it would be a Metcalf or some of similar capacity. It can function fine as a daypack and with the right loading can handle a week or more of gear for long trips.
Great all round pack. I have other day packs but the metcalf is my go to for everything From western hunts to whitetail packing in tree saddle and climbing sticks and taking it up the tree with me.