I have an older MR Metcalf (gen1) and a KUIU 3200 (I can't remember if it is PRO model or not).
On my son's upcoming elk hunt he'll be using the 3200 and I'll be using the metcalf. Overall, I prefer the metcalf. I tend to use the 3200 for day outing early season archery hunts. For rifle hunts and later season, I prefer the metcalf. More room for later season (rifle) hunts, seems more durable, and for me it is a bit more comfortable under heavy loads.
I've packed out entire coues deer bucks in both packs, and for that application, I'd choose the metcalf. I could fit an entire coues deer buck in the 3200, but it just didn't seem as robust of a pack, if that makes sense.
My son usually uses my old 1850 (first gen) pack, but for his upcoming elk hunt he's switching to the 3200 to have a bit more room in the pack bag.
The metcalf allows me to do multi day trips as well. The most I've done with it is ~9 days in early season CO for archery deer, sharing some gear (tent and stove) with another guy.
I like the changes on the new model and am tempted to get one while on sale, but I need to sell an old MR Longbow with NICE frame first. (I have WAY too many packs.)
Nothing really wrong with the KUIU 3200. I like the pack and layout of the bag, but the biggest pro of the 3200 over the metcalf is pack weight. The metcalf compresses down nicely. I have a pintler bag, but lately have just been using the metcalf bag and not worrying about swapping them out.
If I was to choose ONE pack, it'd probably be the metcalf.
Hope my ramblings weren't too confusing.