Huge difference on both sides. 8mm more inducer and exducer will really make a big difference in how the two feel. Even though the housings are the same size the internal wheel size still can make quite the difference in flow. To really use the large one you will have to rev it really high and run high boost, the other one less so. What is the engine size and compression? What do you want to make whp wise over all? If you don't plan on making 400+ whp go smaller than both.
Audi s4 guys use the a single 58/58 or 62/62 and thats a 2.7L. With stock compression and displacement some still think the 62/62 lags too much. All I'm saying yes the bigger turbos will work, but give up some nice midrange while not making much more power overall if you don't really turn them up.