The Zoom H4's successor is being released, so I'll ask the question early: What is the quality of its preamp. I am planning a project using a 5D Mark II, which requires me to record audio via a double system in order to avoid the AGC/onboard limiters of the camera. Is the Zoom H4n's preamp signal-to-noise good enough for professional film work, or am I still going to need to use an external preamp?

The Zoom H4's successor is being released, so I'll ask the question early: What is the quality of its preamp... Is the Zoom H4n's preamp signal-to-noise good enough for professional film work, or am I still going to need to use an external preamp?
I think your question is *early*! So far as I can tell online, there is no announced shipping date, and there have been no units reviewed outside of on-the-show-floor at CES (NAMM?). I don't think anyone yet knows how good the preamps are. Another important question is what quality of clock chips were used.

Having said all that, my H4 will be for sale in the classifieds as soon as I can get my hands on the H4n. I've gotten an incredible amount of use out of my H4, and the addition of "better" preamps, better buttons/controls, and BWF timestamp on files is more than enough for me to make the upgrade.

But I think we're going to have to wait - weeks? months? - for independant reviews. If you have a 5D project in the next couple months, at a minimum, you might consider renting something...

The Zoom H4n is available.

The Zoom H4n is available.
Most user reports are in this thread: http://www.dvinfo.net/conf/all-things-audio/145625-new-h4n-recorder.html