I waited a long time to purchase the Rumblex Plus 4D. Glad I have it. Nice way to start and end the day. Feels very sturdy and stable - size is big enough for a 6' / 200 lb man to feel comfortable on, but not so big it takes over the room. It is generally quiet, but in some modes it is not "whisper quiet" and does make more noise. It could just be our small house, but if using it, people know - but it isn't overwhelming amount of noise. Of all the fitness equipment we own, this is the one my husband will use and that says a lot.
I just upgraded to a Rumblex Plus 4 D plate. Pretty amazing. I am 72 and this is like cheating when I workout. Helps with my joints and conditions my legs and core while I watch TV. The Rumblex has more power than my previous unit, is a bit larger and quieter.
Worth every penny! I do a lot of sitting and just 10 min a 2x a day for upper and lower is so helpful in getting the blood flowing. Just that alone makes it worth it.