Hi ecuguru,
If you have visible impressions in your mattress that are deeper than the warranty exclusion (probably 1.5") and your warranty is still in effect (the length of the non prorated part of your warranty is probably 10 years) I would talk to the retailer that you purchased from to initiate a warranty claim. They will generally send an inspector to measure the depth of the impressions in your mattress and to make sure that they are deeper than the warranty exclusion and that you have met all the other warranty criteria as well (such as having a suitable support system and making sure that there are no stains on the mattress which would void your warranty). Your law tag will include a warranty code which you can compare to the warranty information here to confirm the length of your warranty.
ADMIN NOTE:Removed 404 page link | Archived Footprint: s3.amazonaws.com/simmons-media-prod/documents/Simmons_Warranty_Card_English-2.pdf
The short version is that your mattress is no longer being manufactured so the only way to know whether any other mattress would be comparable in terms of “comfort”, firmness and what I call PPP (Posture and alignment, Pressure relief, and your Personal preferences) … regardless of whether the manufacturer is Simmons or a different company … will be based on your own careful testing or personal experience although this would be very subjective.
For the longer version my reply would be the same as my reply in post #2 here with “Sealy Posturpedic Firm Pillow Top” replaced with “Simmons BeautyRest Worldclass”.
As you can see I would avoid any of the major brands including Simmons and focus on mattresses that are just as “comfortable” but use higher quality and more durable materials that are in a better “value” range.
If you let me know your city or zip code I’d also be happy to let you know about any of the better options or possibilities I’m aware of in your area.
Phoenix