In the last few weeks, if there is one keeper (other than De Gea) who I've seen the most in the league, it's Henderson. Unfortunately, if we're looking to replace De Gea with him, he doesn't seem to be completely error free. Even yesterday against Southampton (0:30 in the video below), De Gea would've been crucified for this.
Now I completely believe in the kid but just because De Gea isn't doing great, thrusting him too early in the United team can be harmful particularly if he makes a few mistakes early on. Most of the people on this forum who are looking to put Henderson as our No.1 just want De Gea out and are thus overrating Henderson. It's true that his stats, particularly the xG one is quite convincing. But over the past few weeks, from the top of my head, he's made errors against Southampton, Newcastle, Arsenal (FA Cup). We should be quite careful about how his development needs to take place.