I kinda miss the Bay station idea now that they're positioned that way. If this is a binary choice, I'd rather it be between one Bay station linked to both Line 1 stations, or two interchange stations at Queen and Osgoode with the Relief Line platforms shifted 'outside the U' (east of Yonge, west of University). Not what's proposed.
it's ~600m between the two Line 1 stations. Assuming a 175m long Relief Line station box, you're looking at 200-250m walk to transfer. It's long, but not impossible. But we're also talking about a Relief Line; how many riders would be bothering to transfer to/from Line 1 anyway vs. just walking to/from their origin/destination in the core?