I went with neither, didn't like the style or the basic functionality of both units. The unit will be visible at the front of the house and wanted something that had at least some aesthetic thinking be applied during its design.
I went with a myenergi zappi, scheduled to be installed in a couple of weeks. the only drawback I had was finding one of their approved installers was a bit of a pain the ones that cover my area were very expensive the national installer was frankly ridicolous, in the end I contacted someone from a surrounding area who quoted a more realistic price, after the grant I'm paying £300. Which is about how much more the Zappi costs over and above a basic unit.