Hi ATX2014,
If you look at the top 5.3" of this mattress then you can see that 3.5" of it uses polyfoam that is less than 1.8 lbs which would be more than the guidelines that I would normally suggest for a one sided mattress of “around an inch or so” that are in post #3 here. The quilting layers by themselves are “on the edge” but by themselves aren’t more than the 2" or more which would be a bigger cause for caution but there are an additional 1 3/4 inches of polyfoam that are about 1.5 lb density underneath the top 1.8" of latex that would also affect durability which would put it over the threshold I would be comfortable with in a mattress in this price range even though they are deeper in the mattress and underneath the latex which would add to their durability. If you were in a lower weight range then this may not be as significant an issue and the specs are better than you would find in many major brand mattresses but they are still what I would consider to be “marginal” or “risky” for a mattress in this price range.
There isn’t a way to quantify or predict the useful life of a mattress relative to each person because of the many variables involved (see post #2 here). One of the variables also includes where you are in the range of comfort/support that is suitable for you and how quickly any foam softening takes you across the thresholds between “sleeping well on a mattress” to “sleeping OK” to “tolerating the mattress” to “deciding to replace it” which are all very subjective and relative to each person (see post #2 here). It would be fair to say though that it would be less durable than a mattress that used higher quality materials in the upper layers of the mattress and didn’t have the same “weak links” in their design (including the mattresses you were considering in your previous post) and that in the budget range you are looking at it would be a more risky choice.
The main pillow thread here and the links it includes to some of the other more useful topics that also discuss pillows should be helpful 
Phoenix