Own the Olympus 12mm, DJI 15mm and the Olympus 25mm. I think you could probably get everything you need out of the 12mm and the 25mm Olympus. Sometimes when filming in tight areas I pull out the DJI 15mm cause it keeps everything else on set just out of frame. I have never needed more. Every one loves the 45mm however I think that the 25mm is already a handful on the sticks to be super smooth and you can see shaking if there is substantial wind so a 45mm will have very limited uses, in my opinion (I have only used the 45mm a couple times and returned). Zoom is worthless in my opinion, lesser quality glass, stick to primes and get to know your lenses and when to use each one. If I had to choose one I would still go 12mm Olympus especialy if you are single op. When I used to shoot with the GH4 on the S800/S900 the 12mm was always the go to lens but we tend to shoot a lot more tracking and action sports material. My usage is 12mm=80% 15mm=10% 25mm 10% . Also to note all three lenses share the 46mm filter diameter the 45mm uses a 38mm I think so you need an adapter ring for your ND's. Also plenty of good used glass on Ebay, I purchased a couple lenses for 60% off the new price so If you don't like it you can resell without a loss. Or do Amazon and BH and pay the price and try for 30 days and make a decision. Good Luck.