Personally I like the 60/85cc combo. The 60cc saw is light enough to limb with yet big enough with a 18" to cut up to 24" stumps. The 85cc saw is more comfortable cutting the 24" and larger trees and up through 40" with a 24" bar. I won't come across much wood larger than that and if I do the 85cc saw can accommodate a larger bar if I can afford the doughnuts.
If I already had a 50cc saw I would be looking at mid 70cc's just like you already are.
If I already had a 50cc saw I would be looking at mid 70cc's just like you already are.