I have the basic one. (I've checked out all three of the Prodigys). I find it very tweaky to get it right. If not adjusted well, the polymer tip can leave a mark on the record. When working properly, it cleans well. Experiment first with cheap records first to get it set up. It's certainly a cool unit to look at, too.
The basic unit is not silent. It's moderately noisy but not nearly as loud as a VPI type machine. But the VPI machine is one you'll have on for 15 seconds at a time. This one will be going for about 2:30 per side. The Plus is slightly quieter and a tad faster. The Blue is the real step up. It cuts a minute from the Basic's time, plus it really is just next to silent, just barely audible.
These aren't built to the standards of his upper level machines, but they're user adjustable and users can replace the parts if need be, unlike the upper level units. The unique aspect to all of the Monks record cleaners is that once an area of the LP is cleaned, that area is not touched by the cleaning mechanism again. With the VPI type machines, the same velvet lipped wand that passes over the record to pick up the applied fluid passes over the entire record a few rotations until its dried. And potentially the lips can hold particulate matter along the way, possibly redepositing it on another part of the record. That's the theory behind the Monks design anyway.
Monks was the first RCM. Harry Weisfeld of VPI, in response, wanted to create a less expensive, faster machine. And he did. VPIs (and the like) clean a record in about 2 minutes total including the spreading of fluid. The Monks Basic will take you short 6 minutes total.
The Monks DisCovery fluid is essential. I compared it to two other fluids, the VPI as well as the L'Art Du Son concentrates. I cleaned several LPs, using one fluid on one side and another on the other. The Monks fluid consistently left the background blacker, allowing the sonic images to have more depth. It's not cheap costing about 25 cents/LP, but in the long run, it's worth it assuming you only have to do it once.