The datasheet for i3070 can be viewed HERE and for i6550 HERE . A point of interest to me was the fact that there is no way to tell the device model or even determine if it is connected and functional or not, until you try to "claim" the device (at which time the device returns a hardware signature which contains the model name and OPOS version). Of course the above conclusion was the result of some 20+ email communication back and forth with Ingenico and several phone calls.
Another issue which came up was due to the difference in display screen size, since the i3070 has a much smaller screen then the i6550. My goal was to support both model Credit Card Readers in the .NET Application I was writing, which I was able to do easily using POS for .NET. The font size for the display text however, is something I have not yet been able to change (and there doesn't seem to be an obvious setting to set it anywhere in POS for .NET library. More to come!