Are the Nitty Gritty vacuum cleaners...

This is true, but the brushes need to be at the right tolerances to get into the grooves, and be gentle enough not to damage them.

I have a Nitty Gritty. But I prefer to wet clean by hand with the MFSL brush and fluid. Then I just use the Nitty Gritty to vacuum the wet records. This produces better results for me. Have never used any other machines, so cannot comment on them.

I do the same as dmgrant1, i have a mini Pro 2 (solid oak) for approx. 10 years and it works like a charm. Never had it serviced. I use the Disc Doctor brush and solution to scrub/wet the record. Then i rinse the record with purified water. Then i put it on the minipro 2 and suck the water both sides at once. No need to turn the record over. Fantastic!!!! I could not live with my minipro 2.