Personally I thought season 2 was stronger. I found only two episodes in season 1 to be especially memorable: "Spock Amok" and particularly "A Quality of Mercy" (which I do think has been the finest episode of the Kurtzman era). Season 2 had four strong episodes IMO - "Charades", "Those Old Scientists", "Under the Cloak of War" and "Subspace Rhapsody". 4 out of 10 is a good percentage, but - as you point out - it should be easier to produce a higher proportion of strong episodes in a 10-episode season as opposed to a 24-29 episode season.
SNW wins brownie points for doing a live action / animation cross-over episode and a musical, but loses some for playing it safe in all other respects. It's the most overtly "conventionally Trek" modern show (after maybe PIC season 3 which was pure fan service with little interesting about it). Granted, what SNW does, it does with confidence and some measure of flair.