I have a 13 Mini and was thinking of upgrading to the regular 15, mostly for the camera.Well I called it. After some side by side tests my intuition is spot on. There is zero difference is quality between the 13Pro and the 15 with the regular lens. The 24 megapixels on the 15 Does Not resolve more detail than the 12 on the 13Pro. The Ultra Wide is worse on the 15 by a small margin which is what I predicted based on the difference in light gathering.
The weight difference is drastic which for me is important. It feels like half the weight even though it's only 33 grams lighter. Bottom Line do not upgrade for the cameras as you will be disappointed. 48 Megapixel file is a joke, it looks gross and I'm never going to use it.
Would the same statement apply, in regards to the regular lens? I don't know how different the 13 Mini and 13 Pro were for the regular wide lens (the whole camera module on the 13 mini is the exact same one that's on the regular 13, and I believe is the one that was on the 12 Pro Max)--- but I was thinking that the 48mp would make a significant difference, making my phone something I might go to a bit more for landscape photography out on hikes, to avoid carrying my DSLR quite as much.
But if realistically it's not going to be a noticeable difference, then it seems not worth the upgrade since my 13 Mini is a fantastic phone and I had no other real reason to upgrade.