How is the safety spot responding to the new sim changes? I know the reaction time for secondary isn't as easy as it was previously. Requires more vision now. I dunno though. I haven't seen many games from the new sim change
FS - I'd go agility...especially if you are in man coverage a lot of the times. SS - I'd go vision...especially if your team has you in zone and run support.
Definitely agility, and this is from a big vision touting guy.. You'll reap the benefits of agility versus vision in the earlier portion of your career.
It's never really about taking vision over agility or speed, it's about not ignoring it to get extremely high agi/speed.