How stable is the frozen stretch?

[RavenLX]

I am thinking about trying out Stretch (Debian 9) in either a spare 
laptop or a virtual machine. If I like it I might just point my sources 
list to that repo on both laptops if it's stable enough.

My question is, once it's "frozen", how stable is it or is it still 
pretty much not suitable for production yet? I also use a couple 
programs from outside ppas (*gulp!* :-O) and am taking into 
consideration conflicts with those as well. They do work great with the 
current stable.