I bump into a lot of reviews on smartphone cameras. This is because of the nature of cameras and smartphones. Cameras especially have dramatic differences when the results are viewed under different conditions. Note the reference in this review where they mention the iPhone is already six months old and getting behind.
For business use, if you’re cautious about getting the exact phone that works for you then you have some work. You will need to survey all situations and conditions that you will possibly encounter from weather to lighting to subject matter. How close and far away are you? What artificial lighting will or won’t you have? Is it real-time and fast-moving?
The point I will make is that the technology changes fast. The need you have for photos may be just documentation. Or just web photos or client communication. If it is not critical but you want to factor a camera in your phone selection (and not just price) then search for smartphone reviews. I suggest looking at Gizmodo since they have frequent unbiased camera reviews. Otherwise just get a smartphone and use it a year or two and if you don’t like it then suffer a while and then buy a new phone.