I'm a fan of the Tascam DR-70D! The issues are all worked out and you just need to update the firmware to v1.13 and then use an approved SD card[or ones we've been using successfully on ts.com], and you should be good to go! They can be had for under $300/new, or under $200/used! Its has 4 XLR/1/4" combo jacks[Phantom Powered Inputs, as well as a regular MIC-IN w/ out Phantom, and a LINE-IN] and is a BREEZE to run with an external USB battery!
I have run both my mk41>KCY>VMS02IB>70d and mk4>PFA>70d preamps, numerous times over the last year, and I can BARELY hear a difference in my Schoeps pre and the 70d! As always, YMMV! I have numerous recordings on archive.org that you can check out with BOTH preamps of mine! And most often, especially outdoors, I prefer the mk4>PFA>70d source
My Phish MMP Night 2, I ran both setups as usual, and not only myself, but the DL'ers, preferred my mk4>PFA>70d source
For the price/size/quality of preamps, there's nothing else even comparable IMO! And now with the new v1.13 firmware, everyone's sd card issues have gone away! I have run flawlessly on even older firmware, since last summer when I got my PNY Elite SD Cards! Once everyone started using the same SD cards, the issues and "Write Timeout" errors seemed to vanish too! As with most devices, its just picky about what SD cards it likes
I JUST sold my last M10 and bought a 2nd 70d + 64gb PNY Elite 95MB/s Class 10 card, because I like my 1st one so much
My new to me[12 hours of use] used 70d will be here today! I'll be running it almost 24/7 to see if its as SOLID as my 1st one
And the external USB batteries are super easy to get and power the 70d for very long periods, even at 24/96 on all 4 channels
And they run forever going VMS>XLR>70d LINE-IN on just 2 channels, even at 24/96!
Here's my most recent bookmarks from the last 5 years
You can easily find the different sources since I left a comment on every UL with the source info
You should find a ton of mk41>KCY>VMS02IB>70d and mk4>KCY>PFA>70d sources very easily
http://archive.org/bookmarks/diskobean