Very nice to meet you, glad you enjoyed the Puma, I like that particular rig as its so light and flickable, My Trek is a bit more of a handful!
Yes the low down torque and hill climbing is very good on the Puma as is the top speed, I get 24mph, the BMX Puma is a faster motor and would do more like 28 or so, it has even more low down grunt but is noisier, the Puma is very quiet, it has the usual hub motor burble when you first start off 1-2mph then it clears and pings along.
As far as comparisons go, the X5 is faster per volt but doesnt accelerate as quickly and doesnt climb hills as well at the same volts, the X5 at 37V is pretty tame to be honest.
Dermot can testify the Puma is light, I can lift the whole bike with 1 finger, its handy when carrying up stairs or over obstacles, my X5 bike is very heavy, but then its faster on the flat, a great motor still.
Maytag raced his bros X5 and the Puma won, I think they videoed it somewhere, the X5 should be able to take more power though if you want to go down the road of electric motorbike, the Puma is a high end assist motor still, not really a motorbike motor like the X5.
We must meet up again Dermot, we can meet half way somewhere on our bikes and have a pint, as it was fascinating talking with you!! you must stick around as someone with your knowledge and enthusiasm is of great value to the forum here! I can bring the Raleigh in with 72V and you must have a go in the KMX at least in a car park if not on the road!!