I am very active and outdoors a lot. I go running, cycling (mtb, road, and cx), climbing, and parkour. For my job I am outdoors walking around all day and doing some dirty work.
Running and cycling: most of my excursions are less than 4 hours (on bike at least). I would probably use GPS a lot and would like a good range of accessories that can work with bikes and armbands. Also a good, rugged case would be awesome. I also plan on doing some day trips that would last 5+ hours or even bike camping that would take me overnight.
Work: Since I work outside for almost 8 hours a day I will not have an outlet to use (I have a portable charger though). Then I will be at the gym or going running/cycling. So battery life is important. I will also have a lot of equipment on me so weight and bulk is a factor.
The mini would be great for size constraints of cycling and running, so I don't have to shove it into a tight pocket. I could also fit it into my vests or carriers more easily, especially top tube bags that are generally small. The smaller phone would also be great for work so I don't have one more big thing to lug around. The maxx would be great for battery time.
I have a Droid 4 now and the battery has been acting funky after 2 years. The phone is also experiencing a lot of lag recently (one week before my upgrade). So I'd like to get an upgrade and keep the 4 to use as a music device pretty much. I would use it for music, gps tracking (maybe directions with OSM to help save battery of new phone on bike rides) and playing games that aren't linked to my accounts (stupid Star Wars Tiny Death Star...). Are there any other good phones I should look at? How is the battery on the new mini? I would also get one or two portable batteries for trips and to have anyway, so if the power of the mini is similar to the Maxx that may be a factor. I don't stream music or movies, so screen size and resolution isn't an issue. I don't take many pics. But I play small games and use the internet often. Is the processor, ram, or internal memory better on one over the other? Which is more likely to continue getting upgrades? What has the best accessories for my needs?
Someone else said to check out the LG G2. Another idea is the Galaxy mini series.