Just got Zoom H6 couple of days ago. Never owned any Zoom model before so I cannot really make any first-hand comparisons but at least it is said that Zoom has made some improvements on the noise-floor issue which seemed to trouble some earlier models.
6 inputs: two inputs (named L+R) are dedicated to Zoom's own mics (there's two different types to choose from + couple more which you can buy as extra) and four inputs for XLR/plug. So far I haven't tested how nice it deals with line in sources but there's -20 pad dedicated for that use. Apart from obligatory low cut and compression choices, there's not any additional effects and I think it's quite nice because I don't feel like paying extra for some half-assed onboard amp modeling or reverb effects which I propably never use. By the way, I was quite surprised to see how many different low cut options there was - 10 different options between 80hz and 237hz. Three different compression presets + another three limiter presets. It really bugs me that manufacturers rarely state clearly the parameters of compression settings (mainly threshold levels & ratios). They are mostly just named like 'vocal', 'general' or 'drum'... just like in Zoom's case. Luckily I found those details elsewhere (some dude emailed Zoom and asked them).
The unit itself feels quite solid at hand. Dedicated volume buttons for each intput is easy to reach but there is always a danger of turning them accidentally since they are quite close to each other. I've learned that accidental volume changing should be avoided by 'hold' fuction... BUT... H6 hold function prevents everything else but turning volume knobs which seems to me like a planning error.
As usual, many functions are hidden inside menu structure which usually is a little bit pain in the ass but longer you use the unit the quicker you get at handling the menu. But there's one thing I miss in every recorder: a quick 'undo' function. We all make shitty takes once in a while... don't we? I'm still a little confused about the whole file structure in H6. If I had a project with for example all six tracks recorded, and I feel like erasing one of the tracks... I haven't found any other way than overdubbing or silencing it at the moment of downmixing or exporting. Just an example of some practicalities which at the moment annoy me a little bit.
Screen is quite small considering you have to see six tracks there but so far I have dealt with it. The only questionable thing is the visibility in a plain sunlight. One of the most criticed aspects is the ergonomics of the unit, because the screen is situated so that if you are recording (by using unit's own mics) yourself playing for example acoustic guitar i.e. sitting in front of the unit, it's impossible to check the levels while playing. So that must have made a large amount of folk musicians mad (nothing wrong with that, pardon).
Powering is by four AA batteries or via usb connection (computer, AC adapter). I use 13000 mAh power bank which is a nice way to power up the unit especially when feeding phantom power to external microphone(s).
There's no internal memory. All data will be saved to SD card (up to 128GB - but as usual, the bigger the card capacity - the bigger chance of audio drop-outs etc. unwanted stuff). I use the attached 2GB card which is easy to get filled. Luckily I have three or four of them.
There's two microphones included in the package: X/Y mic and mid-side mic (which is a new approach to me). After quick testing both, it seems that the volume needs to be cranked up quite high on both - or get as near the source as possible. Or use external mics. X/Y mic sounds good. Mid-side has slightly more self-noise and therefore many users have declared it as a marketing gimmick with no real value of use. As far as I noticed by using just simple Audacity plug-in, the noise here isn't impossible to clean out in DAW. Besides it feels like the unwanted noise issue affects mostly side mic. You can actually adjust the level of side signal onboard (or in DAW by using free M/S converter plug-in). I really need to inspect this whole mid-side approach a little closer since it's fairly new to me. For those unaware: mid-side mic here consists of one 8-figure mic pointed to side(s) + a directional mic facing forward. Together they create (after some confusing phasing processes etc.) a wider sense of stereo field - for example recording an artist from audience while a directional mic picks the sound from stage and 8-figure mic picks the audience ambience from left and right (if that's what you want in the end).
One more interesting thing about this recorder is that you can use it also as an audio interface via USB connection. Tested it quickly, in a stereo mode (2 in 2 out) worked fine with Windows 10 laptop, multitrack mode (6 in 2 out) made some unexpected loud sounds. There's always possibility of having driver related or settings related issues so good luck if you feel like using H6 as an audio interface. No need to try older than Windows 7 since it doesn't work that way with them (but as an external HD it worked fine with my trusted old Windows XP).
When finished with recording project, I'll propably transfer my files independently to DAW and make final mixes there, or if I feel like mixing my stuff onboard (meaning I don't need to add effects to any tracks) I can make a stereo downmix (or several of them) and export the downmixed file(s) to DAW for final mastering. As said before, there's no any fancy effects included. You can only make basic mixer settings for your project, like panning and leveling or changing pitch of individual tracks without affecting the length. You cannot make fade ins/outs, you can only trim starts/ends or divide projects - very minimal.
Talking about leveling, there's one thing that I find rather annoying. There's no master level meter. Or if it is there, it is too well hidden and there's no mention of it even in the manual. When having one stereo track it's no problem but when you have a project having six tracks full of shit, it would be nice to have some hint where the overall levels are. That's no problem if you transfer them all to DAW, but that is a problem if you feel like downmixing it.
OK, overall it is a nice product and I'm happy I got it for such a reasonable price (325€ - compared to Thomann's price tag of 399€).
PROs: Sound, enough inputs, build quality appears to be good, volume knobs are easy to reach.
CONs: Sometimes volume knobs are maybe 'too easy' to reach, 'hold' function doesn't inactivate volume knobs, no quick 'undo' function, no master level metering
