The uplift is a different experience than going for a ride up hill and down dale, which is essentially what you will be doing, albeit repeating the same hill and dale, they are two different things. If you have a DH bike and want to save your energy for the downs then you will find the uplift brilliant, if you are fit enough to do 15 climbs and 15 descents in a day then all power to you, I personally find after 15 descents I am pooped. I wouldnt want to have had to climb up every time too.
Its a money/choice thing.
edit: someone up there said height gain is 150m, well x15 is 2250 vertical metres of climbing, umm that is a lot. I measured top to bottom on my phone gps as 40m , which is still 600m on a full day. At gawton we measure 120m and did this 11 times in a day. I was a dead man after pushing my bullit up that..