If server is properly set not to respond to getstatus (etc) everytime (thus even milions of times per second, generating insane net usage), but let's say max few times per second per ip (there are ways to achieve this, such as iptables, jass, or in my case modified (recoded) aluigi's myproxocket), then it's usability for rddos attacks is pretty much zero. Also, recently there was nothing heard about issues with GT-related rddos, maybe the problem is non-existent for now.