Yes, I evaluated the new Buzz Flutter before enter in the Xamarin world.
when someone says that there is no cons, I doubt it. Only testing for a long run.
There is for sure issues.
For instance, because it's new, there are missing important plugins (in time maybe they will appear)
For instance, there is no separation between view and code behind (this is something like 90's).
About Hot Reload, I'm glad that Flutter brings that to the table.
We have now Hot Reload + Hot Restart (another concept) in preview in Xamarin.
I'm not using because it's not final version.
Flutter need to cook more 1 or 2 years.
Some manager decided to remove too soon (that's my opinion).
In time this may be will be fixed but my impression was made by this mistake.
Google, like Adobe, likes to kill programming languages.
I will not bet at this time.