Moderator, Air Canada; FlyerTalk Evangelist
Join Date: Feb 2015
Location: YYC
Programs: AC SE MM, FB Plat, WS Plat, BA Silver, Marriott Plat, Hilton Gold, Accor Gold
Posts: 18,990
OP, if you want to sit in J, use your eUps. As yvrgary said, you need to be strategic about it, but the only way to have a high degree of confidence you'll sit in J is to pay for it or use the eUps. Op-ups (what you refer to as "free" upgrades) happen occasionally, but very rarely, and can't be counted on.