Bennett doesn't compare to O'Connell in terms of actual game stats, it's true. Our player is a QB2 at best and inferior talent to him. But there's a lot to playing QB in this league, and sometimes you can get a backup to a point of high efficiency where he could potentially outperform the better talent due to grasp of the offense, having a strong connection with the staff and caller, etc.
I like where we're at with Bennett right now as a depth option. It's real nice seeing him show that same mentality he played with at Georgia, so he's a backup level talent who has potential to punch up and surprise you. Which is not a bad thing to have at QB2. I think he's a legit backup.
O'Connell is more of a QB1.5 however he hasn't looked like he's in that window of mentality the way Bennett is. So dieter is right, however I wouldn't be in a hurry to add O'Connell and dump Bennett. And it's not like I liked Bennett as a choice coming out, either. Nor did I like giving him a year off. But when a player has that mentally locked in look and he's a QB, even if he's a lesser talent that affects the way I value them.