I had a number of different RCM started with VPI 17.5, Loricraft, Keith monk, Audio Desk, Amari RW-600 (Chinese copy of the Audio Desk). The most reliable RCM on the list the VPI 17.5, Loricraft, Keith Monk.Of these I place the Loricraft and Keith Monk as the cleanest in doing it's job.
As for the Audio Desk is the most unreliable machine on the planet I have had to send it back 6 times to the manufacture and every time he sends me a new machine, till the point it was costing me for shipment, that I sold it off, hear good things about it as reliable but most of these people are to proud to admit that their RCM have been giving problems either the earlier models serial number or the latest so call up grade had lots of problem. Same goes for the Amari RW-600 which I had 2 problems in a span of 6mths. That I ask for a replacement Amari RW-800 as a simple ultra sonic machine.
Oh! and one point I like to make is the Audio Desk and Amari RW-600 are not true Ultra sonic machine I have not found a transducer in any of the models. No ultra Sonic amplifiers, as compared to the KL Audio and the RW-800. I have ordered the KL Audio will be in next week. So will see how reliable their machines are.