I own a Yamaha O3D (which I dearly love!!) so getting around the AW4416 when I looked at it in the shop was very easy for me!
This has to be the most powerful portable HD multitrack recorder available at the moment! It offers full automation, fantastic eq, dynamics and fx processing and as far as I'm concerned, quite an excellent user interface. The sound quality if fantastic and I love the fact you can add up to 2 optional I/O cards for different kinds of connectivity. I'd get one with the Adat card so I could directly integrate my O3D into the AW's mixer without any signal degradation.
I feel that the recorder section of the machine is the weaker link at the moment- most notably the lack of sample level waveform editing, lack of certain DSP functions like track normalize, DC offset etc (although time stretching and pitch change are provided which is great). Don't get mor wrong, certain other recording features are great but I'm sure that the above mentioned omissions can and will be sorted out in future OS upgrades- please Yamaha?????????????
I love the fx in my O3D and the fx in the AW are even better. having dynamics processing on each track is great but I don't know about using them on the final 2 master tracks. Here I wish Yamaha would add more comprehensive 'mastering' or multiband dynamics processing something like Roland have done with their VS1880 and Korg with the D16. I do believe that this could be achieved in a future OS upgrade!!!!
Its great to be able to add an internal CDR for mastering and backup but I've also heard that you cannot save an image file of the disk onto hard disk (a limitation like on the older Roland VS units). Is this true and if so this should be remedied. But to be honest I didn't investigate the CD burning aspects of the unit so I can't comment about how difficult or easy it is to set up playlists etc.
All in all, Yamaha really have taken the portable studio in a box concept to the next level with the AW4416- you really can do everything from tracking, mixing to burning a master directly to CD without actually leaving the unit!!!!
Lets hope Yamaha continue to strongly support this machine with regular OS upgrades with features that loyal AW users will be requesting. Yes this unit is expensive but then you do pay dearly for quality don't you!!!!