As I said in previous question, you can check that shaping is working by transfering data to target (shaped) host by either copying something (via NetBIOS, SCP/FTP, etc.) or by running simple speedtest (link).
Interface statistics can be retrieved by running
> show interface ge-0/0/0 extensive | match bps
Here is example. Target host interface shaped under CoS section to 50 Mbps limit.
set class-of-service interfaces ge-5/0/13 shaping-rate 50m
I'm then started speedtest on target computer to check results.
Here is speed results without shaping:
After shaping applied: