Bought this for field recordings (rain, storms, seashores etc) and also band rehearsals. Chose the H4 over the cheaper H1 as from the Youtube tests it sounded like the larger mics had the edge in terms recording quality. Also, the two extra mic inputs should be really useful when it comes to band rehearsals and, I'm hoping, to record a drum kit using the on-board mics as overheads and separate mics for the kick and snare.
Tested at a rocky beach on a calm day. The mics are astonishingly sensitive - picked up conversations of passing walkers from 20 meters away as though they were next to me. Not that I was snooping ;) but its almost like aural binoculars.
With the mics set at 90 degrees (can be twisted to 120 degrees for wider field) it gave great stereo imaging and a sense of space, albeit with an occasionally strange telescoping effect of far away things sounding near.
Really impressive sound results in terms of just how much detail, clarity, dynamic range and frequency range there is. Low bass, crisp lower-mids, smooth upper-mids and highs. For want of a better term, what you hear with your ears when recording is more or less what you get on this Zoom. That said, I think it'll take a lot of practice to get the field recordings I'm looking for.
Upon advice of a seasoned Zoom-user friend of mine, I used a pair of earbuds to monitor any wind noise as this can ruin a recording, but I found that on a fairly still day there was extremely low noise and, with the record level set at 80% there was no clipping - although it wasn't a loud environment. I made sure to test this as far away from any roads as possible, not easy as I live in a city where traffic noise is everywhere.
As I haven't yet bought a dedicated wind sock I used instead a pair of spongy pop filters that came with a pair of Behringer overhead mics (useless on their own when tested against a fan), and a child's mitten tucked over the mics. When used together that gave, I'd say, around 75% protection against wind noise without a noticeable drop in response. Not a scientific test, obviously, but good enough for me.
There are a ton of other features on this that I doubt I'll ever use, such as four-track recording and (apparently, but I can't find it) a guitar amp-sim.
Two downsides so far: I haven't yet worked out how to connect this to my 2011 iMac via USB. Bit frustrating as theres no readily available information as to why - maybe the iMac is too old? Plus the Zoom formats the SD card with it's own proprietary format, so not a case of simply pulling the SD car out and sticking it into the iMac. Will try it with a PC instead.
Also, the case itself feels slippery - hence one star less for 'Handling'. Some product descriptions mentioned a 'rubberised' case but it isn't at all. When mounted on a stand this won't be an issue, but generally you have to hold the Zoom rather gingerly when recording to avoid handling noise, so the risk of dropping the thing and smashing those protruding, fragile-looking mics was a constant worry. Maybe I should make some kind of shock-mounted gimbal?
One last thing - it comes with batteries (that don't look like they'll last long) but no SD card. An SD card is vital to operation, so bare this in mind when ordering.
Apart from those little niggles I'm very happy with it. Stay tuned for hours of ambient Hippy music on my Bandcamp page.