The Boss machines often use data compression.
The Fostex VF160ex($899.) is a great machine, very stable, that will give you 8 at once track recording right out of the box. The Yamaha aw16G($999.) is very well liked, and has it's own forum. Same with
the Korg D1600mkII ($1300). The Korg has a fairly easy learning curve, as does the Fostex. I should imagine the Korg's manual is better written than the Fostex's. The aw16's learning curve is more involved. The Fostex and Yamaha are full 16bit machines, with no data compression. The Korg offers the possibility of 24bit, but with fewer tracks at once recording (and possibly playback).
the Korg uses an internal fan that can add ambient noise, the Fostex does not, and I don't think the Yamaha does either. The Fostex's drive is easy to swap out, and there are a range of drives that will easily work with it. The Korg uses a neat touch screen to activate some steps. The screen on the Fostex is the smallest of the group -- though perfectly adequate. The Fostex operating system may be the best of the group. It saves as you go, so that in the unlikely event of a system freeze, your data is still intact. In a year and a half of using the VF160, I've NEVER lost data, ever. The only way I think you can is by yanking the plug during a recording, which is not something I do often.
The Yamaha offers a bigger range of effects and eq options. The Korg and Fostex each have a full 16 mono tracks, the Yamaha reaches 16 by using at least one stereo pair.
Overall, whichever you choose, you can make great recordings, and you'll bond with the nuances and techniques germane to each machine. You could almost flip a coin and do well.