Which fluid should I use

Taters...I use the super deep clean first, then the wash. And yes, I use separate wands for vacuming and separate brushes for clean vs wash...

I've used both. Still own both. There are some differences. I use them on a vpi 16.5 with the disc dr brushes...like you seem to be.

Disc Dr-Takes 3 cycles for me. One with the cleaning solution diluted. some scrubing like they recommend. 2 rinses with distilled water. Results-lowers static some, queit-black backgrounds, some softening of the highs. Which can help is system is slightly bright...

Record Research-2 cycles, quicker cleaning. Seems to bring out more tranparency, more delicacy to the sound. Quiet black backgrounds.

Both bring out tremendous gains in sound. ie, you are not going wrong with either. The sound diff I hear are slight-not monumental.