Hi Coolgranny,
Welcome to the Mattress Forum! 
If you can find out the specifics of the materials inside (see the information you need to know here) the particular Englander Tension Ease mattress you are considering and post them here, I’d be happy to make some comments or help you identify any potential weak links in the mattress.
When considering any mattresses, the first place to start your research is the mattress shopping tutorial post here which has all the basic information, steps, and guidelines that you will need to make the best possible choice … and know how to avoid the worst ones.
Regarding other people’s experiences, I’d suggest you follow the guidelines I linked to above in selecting a mattress and avoid “reviews”. While other people’s comments about the knowledge and service of a particular business can certainly be very helpful … I would always keep in mind that you are the only one that can feel what you feel on a mattress and I would be cautious about using anyone else’s suggestions, experiences or reviews on a specific mattress (either positive or negative) or review sites in general as a reliable source of information or guidance about how you will feel on the same mattress or how suitable or how durable a mattress may be for you. In many if not most cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person or even a larger group of people in terms of comfort, firmness, and PPP may be completely unsuitable for someone else to sleep on (even if they are in a similar weight range). In other words … reviews or other people’s experiences in general won’t tell you much if anything about the suitability, quality, durability, or “value” of a mattress for any particular person (see post #13 here).
Durability is an incredibly complex subject with mattresses and there is no way to standardize that, as there are far too many variables involved. Your best chance at having a longer comfort life is to begin with a mattress using better quality and more durable materials (as described in detail in the mattress shopping tutorial). If you’d like more information about mattress durability, this post goes into more detail.
Phoenix