Bumping this post for the people in the market for a new deck. The F6 can now truly be considered a professional recorder with the latest firmware, and IMHO it represents a much better value than the SD MixPre-II recorders. The only thing the MPII's have the advantage in is accepting a hotter input level, which in practice will not be an issue unless you are feeding it VERY hot line levels or recording very loud sources with extremely sensitive mics.
You won't be disappointed with one of these.
So I've been looking at this deck as an upgrade to a tascam 70D...what would be the benefits in favor for the F6 over the 70D that would justify the cost? I only require max 4 channels max at a top end of 24/48 as a field recorder. Thanks. Chris K.
As someone who used to own the DR-70D, I can tell you the F6 is a huge upgrade in every aspect. The preamps of the F6 are far more transparent, much lower noise, the build quality is much higher, 6 XLR inputs instead of 4, more versatile powering options, timecode, etc. The "killer feature" is the 32-bit FP recording with multiple ADCs, so you never need to set levels or worry about limiters (in 99% of applications). Whether or not all that is worth the price depends on what you are recording.
For me, I only do acoustic / classical ensembles; very limited PA if at all. Mostly choirs, piano, and small instrumental groups, but sometimes orchestras and concert bands also. The preamps make a very noticeable difference for me, but it's the multi-ADC / 32FP end of things that makes my life so much easier. Most of the music I record has a very wide dynamic range, and I sometimes am not able to set levels ahead of time at a rehearsal. I am very often performing or conducting the things I record, making this even more reassuring. On the 70D, I would deal with this by recording a second set of safety tracks at -12 dB, but then that would limit me to 2-channel recording. Limiters (especially the type used on the 70D) sound awful for the type of music I record so that's a no-go. No need to worry about any of that with the F6.
If you are recording loud, amplified concerts and do not need more than 4 mic inputs then there probably isn't much reason to move on from your 70D. It's a solid deck.