I had a no-self experience, why is it a good state?
When I told my Zen Roshi that "I didn't exist," he simply tapped my leg and said, "What's that?" I was completely baffled and tongue-tied.

Welcome to the stream.


  “Mendicants, all those who have experiential confidence in me have entered the stream. --AN10.64


If the "world seems to be completely neutral and analytic", this can be due to indifference (i.e., lay equanimity) or renunuciate equanimity. The difference is subtle and warrants further practice and study.


  Therein, by relying on the six kinds of renunciate equanimity, give up the six kinds of lay equanimity. --MN137


Regarding your question about joy or bliss, you might be interested to read about the eight liberations. In particular, the third liberation involves beauty. Indifference cannot see beauty.


  They’re focused only on beauty. This is the third liberation. --AN8.66


The challenge provided by being just neutral and analytic is that one is still beset by choices, and those choices become more and more difficult with greater insight. Here, precepts become increasingly important along with further practice. 

Also study the brahmaviharas.