I've just got my HP Prime. First I have to say that I'm liking this machine a lot; with a long RPL-use background and an appreciation of classic RPN as well I was expecting to find the Prime more awkward, but I find it a pleasure to use. I just hope we'll see some improvements in RPN integration and 3D graphs in future updates.
But I've found a problem with the real calc that's giving me a hard time: every single time that I want to use one of the bottom menu touch-buttons (except those in the center) I press the nearest real key below it! I guess I'll adjust eventually, but then I fear I won't be able to use my 50G, 48GX or 42S!
Thanks to all people involved in the project, and I specially appreciate the information that Tim, Bernard and Cyrille are giving here. Great job!