Hi Fleur,
I second on your statement above. In fact, most "branded" mattress have already included that feature, which is included in part of the features.
For Sealy, that feature is called "Shock Abzzorber Sprung Foundation".
At first, i do find pocketed spring are good when i was looking for mattress. However, when I do more market research and tested out each individual brands at their respective showrooms, I found that pocketed springs has this disadvantage- after long term (>5 yrs), the spring coils will tend to entagle which may not recoil back to its original state of rest. For sealy coils, they do not have such disadv dur to their unique coil mechanism.
Of course, this is something I cannot comment as I have not used the bed for so long time. But end of the day, i do urge ppl during selection, do based on your own comfort levels and budget. Don't for a cheapo one and end up hating the quality of mattress.
To me , sleep is very important. So take care in choosing.