Pinging lo vs eth0, any difference?
 

Is there any difference between pinging my own machine's lo (127.0.0.1) vs the eth0 address?

Yes, much. 127.0.0.1 will ALWAYS work regardless of whether your networking is working or not. Pinging eth0 doesn't always tell you whether it is working, as some thing think "if you are pinging eth0 of 192.168.1.10 and I am 192.168.1.10 then it will be quicker to do 127.0.0.1, and so don't test your network connectivity". A better test would be to ping a router or something else on your network(assuming your goal is to see ifyour networking is working)

Depending on what version of ping you are using, you may also be able to change the source of the ping, which is helpful in other ways.