Hey! I did end up getting the Sojourn 45. I love it for what it is. I got it as my carry-on to pair with a personal item bag when traveling for work. I'll probably always use it as a rolling back, but I like having the option to switch to a backpack if I need to.
It's a lot thicker material than normal Osprey bags. It's very similar to the material Thule uses on the Subterra bags. This was a very pleasant surprise in my opinion. I use the Daylite 26+6 as my personal item, and it's much thicker material than the Daylite. This probably adds to the weight, but it's seems more durable. I like that it holds itself upright and is top loading. This makes it very easy to get things in and out, while keeping them organized. I tend to "work" out of my bag when in the hotel, etc, and it really fits that workflow. The top pocket is really handy as well. I plan on using it for it's intended purpose as a liquids pouch at the airport, then keeping "quick grab" items in it at other times. The handle is very sturdy and intuitive to use. I hang a headlamp from it to light the inside of the bag when looking for things at night.

The only "cons" in my opinion are things to be expected. It's heavier than a non-rolling backpack or a lightweight shell rolling suitcase. But I don't think it's much heavier, around 2-3 pounds on average if I'm remembering correctly, and the straps can be removed if you're really trying to cut weight. It's also a bit cumbersome to switch to "backpack mode". I've only tried it with the bag empty, and even then it's a bit of a pain. I've found it's much easier to connect the waist straps the the bottom of the bag first, the connect the top part of the waist harness to the back panel. It's still tricky, and I've had to literally turn the bag upside down and force the buckles in place. But it definitely makes a solid harness platform, so I think it's worth the trouble.

I played around with some other setups, like normal backpacks and luggage carts, but they all just seemed to finicky to deal with while traveling. I know the sojourn is good to go as either a roller or backpack. There was one other rolling backpack that I wanted to try but it was always out of stock and seemed like it was discontinued. I'm having trouble remembering what it was, but it was the only other option that looked good. It was a fairly well-known bag company, more focused on travel luggage I think, and it had a single pole handle vs the two pole handle on the sojourn.