Hi Kenai,
The Aurora has a fairly thin 2" layer of more breathable memory foam on top with latex underneath it so it would tend to be cooler than a thicker layer of memory foam in the comfort layers of your mattress but of course not as cool as sleeping on latex (memory foam is not as breathable as latex). It would also have a combination of the slow response of memory foam and the fast response of latex which for many people is a very nice “feel” because it would be more “motion friendly” and responsive than a thicker memory foam layer.
For those that are unfortunate enough to have a bed bug infestation a mattress won’t squish them but the type of foundation won’t make any difference with bed bugs.
Dust mites though are a different matter because these are unavoidable and exist everywhere so it’s more a matter of creating an environment that is less friendly to them (they need a warm humid environment for moisture and food).
You can see some of my thoughts about a solid platform vs a slatted or grid foundation in Post #7 here and post #9 here which talk more about this and the possible extra risk of dust mites, mold, and mildew. While I would tend towards a slatted base if there was a choice … in many cases such as an adjustable bed (which I own) a solid platform is unavoidable and in most cases it would be fine. If many factors combined to increase risk of higher humidity and mold, mildew, and dust mites (humid environment, sleeping in a basement, sleeping in warmer temperatures etc) … then the extra risk of all of these together may be a little more cause for concern. If your waterbed has wooden sides that are tight to the sides of the mattress then this would also decrease the ventilation of the mattress and allow moisture to build up more and would be a “factor” that also increased the risk.
The “weak link” of most mattresses are the foam layers on top of the innersprings not the innersprings themselves. If you cut a mattress open that is sagging or has softened in almost all cases the innersprings will still be fine (or any deeper support layers in the mattress including polyfoam) and it will be the foams on top which will be the issue. Latex is the most durable foam material and the density of the memory foam layer will be the biggest factor in its durability (4 lb memory foam is less durable than 5 lb but many people also prefer the faster response and greater ventilation of many 4 lb memory foam). Both the Aurora and Arcadia have the same comfort layers so they would be very similar in terms of durability (you can read about the factors that affect durability in post #2 here). The different support layers and components will have a different type of response and “feel” though.
That sounds like a good plan … and they certainly do have good value … and service 
Phoenix