I have been using iQOO Neo 9 Pro for the last one month. It's a flagship killer with its specs & performance. With the March updates(2 nos) the phone feels optimised. Battery drain is normal since screen on time with super resolution (1.5 k) and other optimising features will effect battery. But it isn't bad. 

I would though point out about a concern in the Camera department. The 50 mp mode on the phone feels buggy. When I take pictures with it the images aren't sharp, infact try appear dull compared to the usual photo mode. Details are washed out, if you zoom in it looks bad. Compared to that the pictures clicked in the photo mode are sharper with good contrast, and the portrait mode is even better both in 1x & 2x.

I request the developer team to look into it. I really love the camera it provides but few of this issues make our experience sour. Hoping to find a solution in the next updates. 🙏