Which machine is best for Video Editing?

Here's the problem. Any new mac will come with Mavericks installed and will probably not allow you to install an older operating system. Although many people are working with fcp in Mavericks it's kind of hit or miss. And if you start having problems, they may be impossible to solve.

Michael makes a very good point here. If you wish to continue with FCS3 (FCP7) you should probably keep both your current machines so you have back-up. If you need a laptop, just get one.

On a side note: Is it only the new Retina Display machines that can output 4k?

I've seen some stuff on limitations on driving 4K screens on the Retina machines and a revision of Mavericks coming that should allow higher frequencies, but outputting 4K is an altogether different thing. It is my impression that anyone short of a major studio is cutting large-format shows in 1080 as a proxy and then conforming to 2K-4K. Probably best to leave 4K playback to a new Mac Pro, the data rates are probably beyond what an iMac/MacBook can handle.

You can do as I do and create a partition on either your iMac or a new MCP. On one partition I run OS 10.6.8, and on the other I run Mavericks. FCP 7 has some gamma issues sometimes in Mavericks, so for color correcting, I shut down, turn it back on and boot into the 10.6.8 partition. I am starting the transition to FCP X but I need to keep 10.6.8 and FCP 7 because I frequently have to revisit past projects. I'm on a 2011 MBP but will likely move to a new iMac.

Not going to work for the OP.

For years Apple has set up boot conditions that will not allow an older OS than the one that was originally shipped with the machine to be installed. This means if you purchase a new laptop that ships with 10.9, you will not be able to install/run 10.8 or earlier.

x

Good to know - and very frustrating. Thanks for the heads up.