Our team runs _the_ largest Go middleware. Checking in external dependencies into your repo scales - you don't want 200+ users hitting Github every 10 minutes, when you can hit the local Git repo on a 10Gbps n/w. Also, using GOPATH with a simple Makefile is pretty much all you need -- unless you don't grok Makefiles. But whatever floats your boat and as usual the latest hotness sells.