Dez Bryant is a superstar WR who can make all the catches...physical/speed/athletic. All the love McCourty gets here is primarily because he is a Patriot and the Pats' best S in a very weak grouping.
A six looks hot next to a two.
Has McCourty ever taken over a game? Bryant has.
This debate isn't even close.
Now I get the logic that certain players hold more value to a team than just their performance measurables...and no doubt McCourty is beloved by BB and staff. Do the Pats need a McCourty more than a Bryant? This year ...YES. But looking at the past 3 years....Bryant has been a more impactful NFL player. In year two, McCourty was considered one of the worst CBs in the league and a target of choice by opposing QBs...that can't be denied.
If NE took Bryant instead, the need to overload draft picks for WR this year would have been unnecessary. And because McCourty failed at CB year two to present, not drafting McCourty wouldn't have affected current the current CB roster.