I will guess the answer...
It will be faster for sure, instead of initializing over and over again the client, it will gain at least some seconds in the long run...
The thing is how to know if is properly clean, say I do a get, then do a get again with the same client, I must be sure that the result is always set, I mean if it's correctly designed will be like that always, and the previous state will be erased and replaced with the new state.
And when doing a Post, is my responsability to ensure that the data I send is the correct one, and the previous data is clean.
So much trouble maybe for a small gain of time.