Which should i buy

I suggest sony xperia XA1 . Large screen and pixel, More cpu power (Mediatek P20), Upto 4 gb ram, 16Mp front camera.

sony xperia XA1 ultra is better.

It depend on you are Android device or IOS device ,

its bassed on ypur compact .that you wish to have very large screen xperia xa1 ill be good

Both are impressive. But I'd prefer sony xperia xa1 ultra because of its is superiority over sony xperia x performance in case of display size, ram, battery life, front camera. Though in case of pixel density xperia x performance is ahead of ultra, ultra is way better than performance. Ultar's optocal image stabilization feature prevents the photos become bluR. Also ulta looks more stylish to me

I do not really prefer XA1 since it is using mediatek processor. Better to find another phone to buy.

I am already using Sony Xperia X and i am quite satisfied with the product, It serves 5 inch display and good battery backup. So if i charge my phone fully then it will run up to hours. Sony Xperia X Dual is powered by 1.4GHz hexa-core Qualcomm Snapdragon 650 processor and it comes with 3GB of RAM. The phone packs 64GB of internal storage that can be expanded up to 200GB via a microSD card. As far as the cameras are concerned, the Sony Xperia X Dual packs a 23-megapixel primary camera on the rear and a 13-megapixel front shooter for selfies. So a big yes from my side.

One plus 5 or one plus 3T is better!