I don't know what a Caldera Spa is but I can tell you the pro's and con's of each. Our pool project is set to begin sometime in the next week or two and my husband and I went back and forth on this issue (he wanted a raised spa attached to the pool, I didn't). Let me start by saying he won and tell you why....we live in MD and the spa can be used all year round while the pool is closed. I prefered a water feature over a spa but by getting the spa I am getting a water feature as well. It will have 2 spillways. I like a spa for therapeutic purposes and didn't feel that a "pool spa" could give me the relief I need from back and neck pain. Our spa will be 7" diameter and will have 12 jets. I could have gotten a bigger pump and put in more jets but 12 is OK. I will load up a few jets just for myself just where I need them. We are using propane (already have an existing tank) to heat the spa and pool b/c I like a warm pool or I won't swim in it. If I had chosen to heat by pool with a different source I might not have agreed to the spa because that would be 2 hook ups which is more money. This pool is already costing us a small fortune but we both feel like we are getting everything we wanted.

The benefits of a stand alone are that you don't need a seperate pump for the jets and you can move it if you don't like where it is located. You also don't need heating source (propane). They are more therapeutic too. You can really make a stand alone spa look nice around your pool by having brick column structure or a "pool house" to put in under/in.

It really is personal preference. There was a thread on here that asked "Do I really need a spa". I suggest looking at it and seeing everyones thoughts.

Megan