Difference between NAD C715 and TEAC CR-H227
In trying to decide which to buy, the main difference that I noticed was the USB capabilities of each unit.
The NAD provides a USB port for connecting to MP3 players, hard drives, flash drives and you can play MP3 from those. It also allows you to record from any source to MP3, though the rates are: 192K Max for MP3, and 128K Max for WMA recording. Okay for recording a radio show, though.
The TEAC includes an iPod dock, and includes remote control functionality for that. There is no USB support or recording capability (at least not that I can tell - the manual is available at the TEAC website).
So, with the NAD you can use any MP3 player (as long as it shows up as a hard drive, I would expect), but if you have an iPod you won't have iPod specific remote control capability. You can also record to a USB drive.
The TEAC gives you an iPod specific docking station that is probably more handy than the USB interface if you have an Apple iPod.
Current prices here in the USA seem to have the TEAC at about $150 less new ($500 NAD vs. $350 TEAC), or if a refurb NAD is okay, some can be found for about $400.
I haven't yet quite decided which one I prefer...My wife has an iPod, but we have several other MP3 players in the house as well...