Hi mattressShoppingSucks.
Welcome to our Mattress Forum! 
The specifications you found on the mattress express site or even on the sleeptronic’s site are not complete enough to allow to make meaningful quality value evaluations and to be able to predict how long you can expect to sleep well on this mattress (assuming that the mattress is a good fit for you when you purchase it and after you have a chance to sleep on it for a while to allow for the adjustment period)
While the mattress is hand-tufted and while the pocket coils are rarely a cause of concern in terms of durability, you’d still need to know the mattress information listed here so you can compare the quality of the materials and components to the mattress durability guidelines here
Generally, in your search for a new mattress, I’d keep in mind that most of the major manufacturers in the industry today are not transparent about the information a consumer would need to know to make an informed decision. They tend to use lower-quality materials in their mattresses (especially in the comfort layers) which will soften prematurely and lead to the loss of comfort and support much too quickly. The mattress shopping tutorial here has all the basic information, steps, and guidelines that the people who visit the forum here will need to avoid these types of issues so they can know what to look for and perhaps more importantly … what to avoid.
The name of a manufacturer makes little difference (good or bad) because all manufacturers use both higher and lower quality materials in their mattresses and it’s always important to make sure that you know the quality of the materials in any mattress you are considering so you can make sure that it doesn’t have any weak links and make more meaningful comparisons with other mattresses. Unfortunately, foam softening isn’t covered under a warranty unless there are also visible impressions that are deeper than the warranty exclusions, even though the mattress may need to be replaced (see [url=The Serta iComfort mattress ... what's the buzz - #176 by phoenix]post #174 here [url]).
If you manage to find the specs about any of the mattresses you are considering and post it on the forum then I’d certainly be happy to make some comments about the quality and durability of the materials inside it to let you know if there are any lower quality materials or weak links that would affect the durability and useful life of the mattress and could be a reason for concern.
Phoenix