SPDY, SSL termination and proxy_pass

I have setup SPDY on my application and have observed some nice reductions in page load times. However in a production environment my setup is somewhat different.

At the moment my setup looks like this:

server 1 running nginx, terminates ssl and uses proxy_pass to server 2
server 2 running nginx, php-fpm and varnish etc. (actual web application)

I have just setup on server 1 spdy protocol:

server {

listen *:443 ssl spdy;

location / {

proxy_pass http://someip;
}
}

Now my question is with SSL and SPDY being terminated on the first server, do I still get the relevant performance improvement from using SPDY from the application that I am trying to use on server 2?

Does server 2 need SPDY enabled on nginx or does it not matter? Do I need to use proxy_pass https:// or https://someip:443 (and thus SSL installed on server 2?) Do I need to add_header alternative spdy on server 1?

On a related note, I am also planning on setting up load balancing on a seperate application. It will have load balancing setup on server 1, with ssl/spdy and then upstream to server 2/3/4/5/6 etc. Will I also get SPDY performance improvements?

Any comments/suggestions welcome!