The question title pretty much sums it up... I haven\'t been able to find any good resources that outline the pros / cons of using Phusion Passenger Standalone for Rails App Dep
Standalone is built on top of Nginx. You can directly attach it to port 80 and it'll behave pretty much like Phusion Passenger + Nginx: it can serve static files very quickly, it'll automatically start and stop processes based on traffic, it'll auto-restart processes when they crash, it'll take care of fairly load balancing traffic between processes, etc. Performance-wise, it's exactly the same as Phusion Passenger for Nginx. So yes you can use it in production.
Nginx does not support .htaccess. It's an Apache thing.
If you run multiple Standalones it's a little bit more memory-heavy than running a single Phusion Passenger for Nginx but the overhead is relatively small.