I have not use REBUSFARM, but have tried some other online rendering cloud and let me tell you, it does not matter how fast their machines are, it is only as fast as the pipeline getting to it and back. With all that extra optimized time, I rather render on my own small harness farm. And with unreal and poor man Enscape plugins, these days of waiting for a computation image is going to be obsolete as soon as raytracing realtime images can be produce mainstream.