If you're a novice flyer, and more importantly can afford it, you might want to look at the P4 but remember that it's not bulletproof and it could be painful on the pocket of things go wrong! My advise, if anyone is set on the P4 is to wait until the wrinkles are ironed out. DJI will not guarantee that you may still crash with the P4 - the collision avoidance technology is only forward facing and most crashes tend to happen unsighted of the camera ie to the sides or when 'backing up' - you won't be coverd under warranty for such collisions.
Personally, unless anyone is a slave to the latest gadgets, is to go for the P3A or even the P3P as we may see a further slight reduction in price of the latter. Learn to fly manually with the control sticks and don't wholly depend on the in-built automation because if things go wrong, you'll need to be able to pull yourself out of danger.
I'm looking at apps for my P3A to give me everything the P4 offers apart from collision avoidance at a far cheaper price tag! Rumours are already emerging that the P4 Active Track feature isn't all it's cracked up to be. Watch the unveiling video where the female tracked subject is wearing bright pink against a black backdrop so that the P4 can 'see' her and that the lad on the bike (who acts as a 'distraction' for the P4), one he doesn't cycle too close to the female and two, he is wearing blue which is more difficult to differentiate against the black backdrop. Results are showing that, in some instances, the P4 'loses sight' of the tracked subject momentarily before refocusing on them. I believe that someone has tested subjects against a grassy backdrop with poor results. Sounds like I'm really putting the P4 down but all I'm saying is to be cautious and watchful, and maybe wait for a while for it to settle in the market