I have the DJI 15mm, the Olympus 25mm and 45mm. I can't quantify it, but my favorite is the Olympus 25. No distortion, excellent color reproduction and sharp as a tack. I guess I just quantified it...
I bought the 45 specifically for lens compression. I have a client who wanted a view of his property that included both a scenic bridge, and the city skyline (6 miles away). He wanted the skyline to look closer to the property.
It does this well, but it's challenging and stressful. The challenge is that the focal length magnifies drone/gimbal movement that is often not even noticeable in wider angles, so making moves with it is way more challenging. It really magnifies the "pendulum" characteristics of the gimbal.
The stress... no biggy if you can stay relatively close to your launch site However if you're limited in where you can launch from, and you have to compose your shot with the drone in a certain point in space to get that lens compression, it's remarkable how far you have to send the drone to get there sometimes. With the 45, it should be a 2 man operation as the 45 is so tight an angle that it's deceiving as a view for piloting. Yes, the FPV cam is for piloting, but for video, one must maintain the composition of a moving shot as well, and it is best that the pilot is not tempted to get tunnelvision on the composition lens view, hence 2 man operation.
I have the Olympus zoom lens (14mm to something, I forget the focal length range off the top of my head), but we bought that one for one specific shot that required an exact composition that the 15 was too wide for and the 25 was too tight for. I do not like using it at all because of the weight. Talk about pendulum action... and stress on the airframe...