DSXchange

Certainly, performance of modify stage is better than transformer .
but transformer has more functions than modify stage , and can perform several work at one time .
if you totally use modify stage instead of transforms in complex jobs , it may make your maintenance harder.

I agree with thompsonp .
Doesn't it work?

I think you can check you network first .
sometimes , when i connect to DS server with VPN , similar problems happened .

If your network is fine , try it as what chulett said : )