This Loblaws location is one of their best. It is gigantic, has tons of selection, and is very clean. I'm not sure grocery stores have flagships, but if they do, this is most definitely theirs (they film all the Loblaw commercials here).
Sometimes there is even live music in the fresh food section.
The Good:
1. Location. It's very central for most people living downtown east.
2. Clean. I've never seen anything but clean and I go to this location quite a bit.
3. Huge. It's so rare to have a huge grocery store downtown so this is a nice treat.
The Bad:
1. Lines. This place is always slammed (especially Sundays) - be prepared to wait in very long lines.
2. Cost. The cost for things here are more than the normal grocery store in Toronto (especially the produce).
Recommendation: come here to get your groceries during off-hours and try some of their fresh food - it's pricey but delish.