I think S6 and S7 have the same amount of great episodes, but S7 has more mediocre eps and stinkers.
Great S6 eps: Chain of Command I & II, Face of the Enemy, Tapestry, Frame of Mind, Timescape
Great S7 eps: Gambit I & II, The Pegasus, Lower Decks, All Good Things I & II
So, 6 each
Mediocre to bad S6 eps: Rascals, Fistful of Datas, Rightful Heir
Mediocre to bad S7 eps: Interface, Dark Page, Force of Nature, Inheritance, Homeward, Sub Rosa, Journey's End, Firstborn, Bloodlines, Emergence
10-3 for S7
S7 has it's share of great episodes but far more stinkers than any season since 2.
Edit: Removing 'Quality of Life' from the list of bad episodes because I was confusing it with Cost of Living. It's more an average episode.
(Remember kids: Never eat your worlds!)