I agree, the step up from the P3A is huge. The redundant compass and IMU are alone worth the upgrade. With my old P3A I constantly struggled with those pesky compass error issues. Never had one incident with the P4. The range is the same (one mile here in Europe).I also went from a P3A to a P4. I find it a major improvement wrt props (quick release), camera (UHD) and body (more robust). You can buy them fairly good priced. You could also consider a P4P or P4A, but it will cost you a lot more.
Don't you work for Built Drones? Seems a bit dishonest to pretend you're a customer.Contact Built Drones and get some professional help, they helped me decide best way to go for what I was doing! Wasn't disappointed with my decision after.