Posting the following for other readers - if you're happy with your upgrade that's all that matters.
Remember that 20% is the area measurement. Marketing departments like to cite area changes since they present an amplification of the underlying linear difference.
Display sizes are 1.9" diagonal for S7 45mm (484x396px @ ~326ppi) and 1.78" diagonal for S6 44mm (448x368px @ ~326ppi). Diagonal difference of 0.12" (~1/8" or ~3mm), which is a 6.7% increase; X & Y axis increases of ~8%.
So of course the marketing department uses the area increase -- it sounds better. 😀