I'd rather they keep him. Brady is 40. Belichick is 64. These guys aren't going to be around forever. I would rather they load up and finish strong at this point.
Yes, Butler will fetch a compensation pick, but there are a couple of issues with that. First of all, the compensation pick won't come until 2019. That means that player might not contribute until 2020 or 2021.
Second of all, compensation picks aren't guaranteed. If we sign a player to a comparable contract in free agency next offseason, we don't get the pick. So in that respect, it limits flexibility. Plus, it's not guarantee it will be a third round pick. Very few players net a third round compensation pick. More likely, it would be a 4th... and pick at the very end of the 4th round.
Butler is a very good corner, and this team is so strong, I hate the idea of taking talent away from it. I'm usually okay with letting players leave for compensation picks, but Butler is making pittance this year and so it's a bit of a unique situation.
I understand the intricacies of roster-building and the need for young, cost-controlled talent very well... but trading Butler seems wrong, it seems akin to prospect hoarding in baseball. I hope they keep Butler, but I fully-expect them to trade him to NO for #32. As others have said, I'm convinced the trade parameters were in place at the time of the Cooks deal.