I used an RX on every HWE job for years. Haven't used it much for the past year since I got a GreenieHorn. A prescrub with a 175 or Brute OP and rinse with the GH is MUCH faster and easier for me, and just as effective. And if you have a helper, one can prescrub while the other rinses, whereas if you RX, the helper is just pulling hose more of the time, which is less productive.
And the RX doesn't get the corners or as close to the edges.
Only time I've used it recently was by myself on a super-nasty plush with lots of open space. And a prescrub and wand-rinse probably would have done as well, and faster.