To any one looking to purchase any of the DJI products that happen to read any negative reviews, let me tell you that I did have a problem with my new P4 where on the secound battery flight, my camera sensor failed and because it was a hardware failure, it had to be returned to DJI US based repair center.
I contacted DJI cutomer service and within 24 hour I was given a RMA number and later same day a prepaid FedEx label. There is a little story about the shipping, but that was my cause and not DJIs. None the less, P4 shipped from east coast (MA) to DJI repair center in CA which was FedEx ground (4 delivery service). Upon its arrival, I recieved on Wednesday April 6, 2016 that shipment was delivered and checked in against my assigned RMA number. Also, in the email I was given a repair tracking number that I could sign into, to check on status and any repair quotes if any, but not expected since it was a warranty issue.   
On Friday April 8, 2016, I received another email that my P4 was fixed, tested and shipped at no cost. Tracking number was supplied and I have to say I am very impressed with DJI service. It was a stress free excellelant experience. Great Job DJI, Thankyou.
Now some of you may say its too bad P4 failed and that I had to go through this. Well, I am a service engineer with 32 years working on the NASA space shuttle and spacesuit program and currently for the last 3 years (since shuttle program retirement) a service engineer for A380 and B747-400 ATA21 systems, my point being, with any high end technology, there are still hardware failures that occurr for serveral reasons and some are known in the aviation industry as infant mortality failures. This is the reason why testing is so stringent in the  space industry to shake out those reasons I could talk about (but thats a big story).  For consumer durable goods, production testing does a great job for caputuring most reasons for infant mortality failures and those for like cameras, computers and tablets for example usually are fixed free under warrenty or are replaced with factory refurbished. I love factory refurbished because all the bugs are fixed and you get a price break. Sorry for long conversation, But the big picture is I am experiencing DJI's effort to really perforrm in the aftermarket support of their product. DJI really stands behind it and quoting a popular youtube vlogger "I believe DJI is the best camera drone on the market".
Very impressed and a big DJI fan for many years since my F550, P3 and now P4.
Addy Overbeeke

Mine's en route to Carson CA now. Sure hope for similar results. I need it for a commercial shoot on the 22nd!!

I've had to send in for repair twice, took 12 days total from the day I shipped till I got it back, and this happens twice with these speeds. I am very happy with the speeds.