I think it's a long time indeed for 20th to really be a retail corridor. There's plenty of shops on 20th today, but that's because 20th is intersected by all of the north-south retail corridors (and emerging corridors) in the area; Edmonton Tr, Centre, 4th, 10th, 19th. Virtually all of the retail on 20th is at those north-south roads. 16th Ave is a retail corridor -- a pedestrian-hostile one, but a corridor nonetheless -- and it has plenty of underused capacity for retail intensification. 20th won't become a thriving retail corridor until there's enough density in the area to support both it and 16th Ave, and that's Beltline levels of density. By that point, these 8 units will be in need of replacement.