Battery: Xperia XA1 Plus offers you more of 730mAh, not much but its okay.
Sony Xperia XA1 Ultra
Screen: Bigger screen means, your video experience would be awesome. You will enjoy playing games more.
Thickness: You can manage your XA1 Ultra easily and looks more fashionable.
Storage: XA1 Plus has a 32GB whereas XA1 Ultra has a massive 64GB storage.
DLNA: DLNA is the new way of sharing and streaming media over nearby devices.
Verdict: Someone has rightly said, to get something, you have loose on something. The battery of XA1 Plus is more than the XA1 Ultra, but XA1 Ultra offers you better features. So, in my opinion, you must go for the XA1 Ultra.
Know your Device. It is important that you learn about the capabilities and drawbacks of your phone. ...
1.Update your Android. ...
2.Remove Unwanted Apps. ...
3.Disable Unnecessary Apps. ...
4.Update Apps. ...
5.Use High-Speed Memory Card. ...
6.Keep Fewer Widgets. ...
7.Avoid Live Wallpapers.
OnePlus 3T vs Sony Xperia XA1 Plus 32GB
Both the phones have their pros and cons,lets analyze:
Advantages of OnePlus 3T
1.More RAM:-More RAM means more applications can run at the same time.
2.Slimmer:-Slimmer devices are easier to carry.
3.Light Weight:- Light weight devices are easier to hold .
4.More Storage Capacity:-More memory allows you to store more songs, videos, photos and install more applications.
Advantages of Sony Xperia XA1 Plus:-
1.Octa Core CPU:-More cores result in better parallelism, meaning more tasks can be processed in parallel without slowing down the User Interface.
2.Better Camera Resolution:-More resolution generally means better picture quality, though it's not always necessary.
3.Supports Memory Card:-Memory cards give your device more storage capacity.
Verdict - In my opinion,OnePlus 3T is better overall performance and price ,if you need better CPU and Better Camera Resolution you can go for Sony Xperia XA1 Plus .
You can also compare these devices on 91mobiles