- peer to peer is slower than client/server?
No. If you can make a peer-to-peer connection, it will likely be slightly (but not a lot) faster than client/server for a message that would go user->server->other user. Some people assume it will be 50% faster, but that's seldom the actual case.
However, peer-to-peer come with a number of really hard problems, including NAT punch-through, cheating, and privacy concerns. It is common that beginners underestimate these problems, and overestimate the potential gains.
- how much it increases the delay using cloud backend (appwarp) instead of normal connection?
What is a "normal" connection? The IP, UDP, TCP, and HTTP protocols don't know whether they are going to a "cloud" location or a "normal" location.
If you are not seeing the performance you expect, you should draw out the different parts of the equation that can affect the performance, and attempt to measure each of them separately. That will give you a good understanding of the problem.
I don't know about appwarp at all -- their technical support should be able to answer performance SLA questions.
All we've seen is that you suggest there is a 80-120 millisecond "latency" when using their platform. However, that doesn't help us answer the question at all.
Latency between what and what? Where is their server? Where are you? Where is the other party? What protocol are you/they using? What are the alternatives you could consider?