Comparing 2 meters based on one reading is like comparing apples to oranges. All meters have to meet certain criteria and some are more accurate at low readings, some at mid range and some at high readings but they all have to be within the standards set by the FDA. On a higher BG, 50 points isn't that much when you consider meters have a variance allowance of 20% high or low in the US. You didn't say what readings you got when testing so I don't know if that difference was on a low, mid or high reading.
My suggestion would be to use the Prime that is reading lower. My reasoning is that if Aragon is heading too low, you will catch the low numbers and be able to intervene sooner than with the One Touch. Keep the One Touch as a back up knowing it may be reading a bit high. The other advantage of the Prime is that the strips are far more reasonably priced.
The best thing to do is pick a meter and stick with it so there is consistency in the readings.