Well, I was just thinking about this after about 9 months of using mine.
First, I'll start with saying it's been better for me than MDI. And I've not had the problems you've mentioned. But I will note that they take a while to learn how to correct for you - eg the first pod doesn't make any effort at all to do anything but the initially programmed basal. This will come up later...
And the support is excellent - when a controller died they offered to get me one later that day, and not necessarily at home. (I didn't need one then, next morning was fine).
Here's what I think could be done better :
Glucose level on lock screen. I don't want to have to type my code in to get my glucose level, especially when wearing gloves.
Activity mode doesn't cope with hard exercise. I'm learning that pausing insulin stands a chance. It would be great to be able to pause while in automated mode to allow the high from some food to be taken care of by the exercise without shoving more insulin in and causing a hypo quite soon afterwards.
No backup of controller data. If your device/controller dies for whatever reason, you're back to day 1 with the aforementioned learning to do again, during which time the control isn't nearly as good. Why isn't this backed up so you can carry on with the same control?
Controller is as sleek and svelte as would be expected from a very cheap mobile phone. Which is what it is. I've got used to the Freestyle Libre reader, which is small enough to keep in a pocket and does its job with just a single button press.
Carrying two fairly big devices around if you've got your mobile phone too is tedious.
Alarms are just wrong. Eg the "pump about to end" one is really intrusive. Yes, you've told me. Quite a few times now. I'll be changing it when it finally times out. But the out of range ones can be too subtle.
Two for libre users :
No ability to display glucose level on another device automatically - eg a watch. I know libre doesn't support this, but it doesn't stop the omnipod controller doing it.
When the pump is out of scanning range of the sensor (happens at sensor switchover time), it would be good if a simple scan with the controller could be used to record a level and allow the automatic control to continue.