I was in a similar situation a few months ago (T2–T1 connection, about four hours, flying out with Latam) and liked the Air Canada lounge a lot better than Iberia's (where I was the only person) or JAL's. I didn't try Cathay's, I think it was closed. Air Canada's is the most spacious of the lot, has the best food by far, overlooks the apron and has great showers. On top of that, T2 is quite a hike from T1, so it's only really worthwhile if you want to stretch your legs.
Then again, if you do want to stretch your legs, four hours is enough time to have a stroll in the city and have an Äppelwoi (cider) next to the river which might be a nicer way to spend four hours if the weather is good.