In the doco online/ grade area, I speak to lots of editors and over the past years the common quote has been “I prefer the AVID but if I am going to buy my own system it is FCP”.
Their two common reasons are price and the fact that they feel more comfortable in their technical ability to install and maintain FCP over AVID. Cost is a big issue in the doco area and lack of tech support that used to be available in bigger facilities but is now being squeezed as they compete with home FCP setups is turning opinion away from AVID.
Also few facilities that I know of here in Australia are exclusively AVID because they know that FCP is what many younger editors are demanding. I sense a generational change but amongst older editors, there is also a sense that FCP is now their preferred system.
That said, as someone who has used FCP for four years and still uses audio systems like Fairlight & dSP, I still find FCP and AVID to be clumsy and very poor ergonomically compared to dedicated controllers.