Definitely, OnePlus 4/5 will be much better than the beast OnePlus 3T, one reason being Launch date is around mid of 2017.
I own Oneplus 3 and my friend owns Oneplus 3T. I have used both and let me share my review about “Oneplus 3T”.
1. Camera: Amazingly fast camera. 4k video(30fps). Full HD at 60fps. 720p slow motion at 120 fps. The Best selfie camera I have seen(16 MP), Its like the best rear camera for selfie.
2. Display: 1080p is good as 2k, except the difference when u keep both together. It's extremely bright.
3. Speaker: It has single speaker, but one of the loudest of all the phones and awesome quality.
4. Battery and Dash Charger: Believe it or not. They are best ever. The phone also charger 92 percent in 60 minutes. The battery backup is awesome for a 3400 mAh battery with doze mode enabled by default. Simply saying, “The phone charges almost 2 percent in every minute(almost up to 60%)”. Because the current is more rather than voltage, the phone remains warm. Only charger gets hot.
5. Customization: U cannot find a phone better in Customization than Oneplus 3T and Oneplus 3 right now. If u say NO, it means YOU DON'T KNOW.
6. Updates: As a flagship device, there will b lots of updates. They have provided many updates and indeed they were listening to their Customers. Custom ROMs are also available…
7. Storage and RAM: 64GB/128GB UFS 2.0 is one of the fastest available. They transfer at an amazing speed with PC. 6 GB RAM may seem too much, but just think it's made for the future.
8. Design: The premium metal used is extremely strong and durable. I don’t use my phone case most of the times just to enjoy the quality.
9. Buttons: The fingerprint sensor takes less than 0.2s to unlock. There are two other capacitive buttons which can be configured for Single press, Double press and Long press. Total 3 buttons with 9 functions.
1. Not expandable: I don’t why people say this as a negative point when they use the same 64GB (32GB internal + 32GB memory card). LOL. Oneplus 3T even has a 128GB model. The memory cards are costly too.
2. Non-removable battery: The battery cannot be removed, just like most flagships right now. I don’t think people would keep an extra battery when Power Banks are common. Also when u can charge ur phone quickly.
3. Software Bugs: Most of the phones nowadays have bugs. But Oneplus has resolved all of them for Oneplus 3, whereas Oneplus 3T is new and no bugs yet.
If you think the above features are sufficient enough, go ahead with OnePlus 3T.
Now that you know the beast now, let me introduce you to the future beast.
Upgrades in OnePlus 4/5 will be:
Processor: Snapdragon 821 to 835. 27% faster and 40% more power-efficient.
Display: Could be curved display. Possibly 2K.
Camera: May be 21–24 MP. Could be dual camera.
Battery: May be 3500–4000 mAh. May be Quick Charge 4.0
RAM: Possibility for 8GB
All the features mentioned above are from the knowledge that different mobile sites have. If you wish to get all the above features (hopefully), you could go for OnePlus 4/5.
OnePlus 5 Release Date: April 2017 (Expected)
OnePlus5 Price: 3000-3500 yuan (in China), Rs. 35,000 -37,000 (in India) and $495-$510 (in US).
Finally, it all depends upon your interests and patience. :)