I haven't got one (but would love one), but assume it's configurable and is a variation as the previous chap said on speed - a reverse calculation if you like, a bit like ETA. Perhaps more useful in running, but if you have a set course and a time to beat (a TT) it could be handy. Doesn't it also have a 'virtual partner' which must use the same sort of calculation as pace in order to measure today against yesterday or your mate etc?
The only way I afforded it was everyone chipping in for Christmas and birthday and adding to it my self.
The visual partner I am not over impressed with but if you want to test yourself against another day it is good. But when I have used the virtual partner the weather played too big a part, hopefully with the better weather coming it will be used again and impress.
I am impressed with the training workouts, from mags and websites I have found several work outs to use on my commutes (I have put a press lap button in a lot of work outs so I say when I start the workout as some parts of the rought it is not safe to start doing intervals) and time will tell if I am putting enough effort in. I have programmed a functional threshold test in to it will all the warm ups in it and it was easy to follow and to get the results as the actual test is one lap and all the info is there. The only problem here is me, I need glasses to read but not to ride I can see the large lettering but the small stuff some times I can make it out others not
The cadence is good and enlighten so there is a work out in it for me to increase my cadence.
I have imported a gpx rought from memory maps and tried to follow it home and it was pants, BUT I was trying to go the wrong way so I thing it was all ways trying to go back to the start and not follow the programed rought so next week I will try and program it the right way.