I took GRE in November.
I booked the at Test Center test.

Experience of test center:
Pros:
1. You can trust the system and internet connectivity. No issues occurred.
2. Gives the exam feel

Cons:
1. The resolution of monitor was so bad. All the text was pixelated. You feel like operating computers in 1990s.
2. Keyboard is different style. Although I got used to it in few minutes and had no problem writing the essays.
3. Center is noisy with keystrokes from fellow test-takers and you will hear the sound even if you use noise cancelling headphones.
4. You are not allowed to take water bottle. I felt this was very harsh.
5. You need to wear the mask and it can be a bad experience if you also use spectacles.
6. They provided pencils for doing scratch work. The pencils were shorter due to reuse and it was hard to write with short pencil.
7. The mouse was too big for my hands and my palm was in pain after few mins of use.

This experience is specific to the test center I booked my exam at and it can be different experience at other centers.
Based on this experience, I personally felt it would be better to book at home test.

Exam content:
I felt the exam was exceptionally hard. Almost for all the questions I needed to think a lot.
There was almost no question that I solved in 30 secs and felt confident about it.
I took almost 10 practice tests before the actual exam and thought the actual test was more difficult.
There were 3 verbal sections and 2 quant sections.
So total 100 questions.
When I saw the 3rd full length verbal section, I was quite surprised. I was totally exhausted already and had no energy for another 20 questions.
And those were not easy as well.
I entered the test center around 1pm and exited around 6:30pm.
It was a grueling experience.

Advice for test-takers:
- Prepare more. Prepare for the worst. My friends kept telling me that real GRE is easier than practice tests and I believed them. But my case was different.
- Build stamina. The real thing can be exhausting.
- When taking the practice test also spend 1 hour for the essays. And do the tests just like real ones. Without breaks. Only take official breaks. The 60sec one and 10min one. It will help build the stamina.

Hope this helps.

I was getting the score around 320 in mock tests but my real score was terrible and probably need to retake the exam.
But I am too exhausted to think about retaking it at this moment. I will take some time to cool off and then give it a thought.

I am thankful to this forum especially Carcass for clearing my doubts and helping me in the preparation.