Hi thealleyplace,
I believe they’re correct and the 400 model is being discontinued (although it’s still on the Ergomotion website).
Ergomotion was just purchased by their supplier (see here) and they also supply adjustable beds to two of the largest manufacturers in the industry (Serta and Simmons) so it would surprise me if they went out of business.
We have owned the previous model to the Reverie 5D (the Reverie Deluxe) for about 4 years and are still happy with it and haven’t had any issues since we purchased it.
I don’t have any experience with comparing the more recent models (it’s been a few years since I did any detailed comparisons) but since all the adjustable beds have the same basic functions and all of them are fairly reliable I would compare adjustable beds based on “price per features” comparisons. There are some comments about adjustable beds in post #3 here and many more in the adjustable bed topic it links to that may be helpful which also includes links to some retailers that you can use as pricing references.
Hopefully some of the other members that have recently purchased an adjustable bed will also see your post and share their comments about the bed they purchased.
Phoenix