I used a Droid for a few days, just before switching to the N900 (ahhh, the good times). I remember that I prefered (a lot) the N900's keyboard. The shape of keys was much better for tactile feedback, I could feel where my fingers were even if they were hiding 4 keys. With the flat keys of the Droid, I never felt so comfortable and the error rate was higher. I'd really prefer any keyboard with concave keys like the N900's. This is not to mention the proper arrow keys and the silent typing of the N900 (some keyboards are very clicky and can't be used in a meeting, this is really important and this aspect must not be overlooked in my opinion).

Of course, if it's the only HWKB OH available, I'll buy it ias soon as it is available. But I think better keyboards may exist, perhaps not as cheap because you would have to buy unecessary parts with it (like BT keyboards for iPhones). I guess this is the problem you are trying to avoid with the Droid keyboard, but to be totally honest, I wouldn't mind throwing 40 more euros in your OH if you could achieve the killer HWKB OH with optimal keyboard design.

Keep up the great work!