Cary,
I have been in the business for over 25 years, like the CSV, have installed 50+ CSV systems and they have issues of their own, especially in systems with high iron and manganese content - though mineral content is likely not an issue with the OP's situation considering he is on a municipal water supply. I know all about the affinity laws, I understand fully that CSV's don't cause the pump and motor to work harder, and I can still say that no one system is perfect for every scenario - even a CSV. As for the total energy use, I was the first person at the first VFD seminars we attended to ask the manufacturers of these VFD's to provide us dealers some written literature showing the real world cost savings a VFD could provide, to help us sell the product, and never once did a manufacturer do that. Once I realized the manufacturers wouldn't put the alleged "cost savings" in writing I made sure our company never used cost savings as a sales pitch - understanding of the affinity laws makes it nearly impossible to believe a VFD will save you money over a CSV installation, but for a typical residential family of four I don't believe the energy costs of the two systems vary enough to matter for most homeowners.
Installing 100's of VFD systems over the past 15 years or so I can say for certain they are now pretty reliable as long as you understand how to install them and set them up. They have not caused us to go out of business or pull my hair out and, if anything, the demand for them in the industry is growing because so many people who have them like them and then tell others about them. That's not to say a CSV system won't do almost the same thing as a VFD (CSV systems don't provide soft starts for motors which is very beneficial for commercial and industrial submersible pump applications and the high total head caused by CSV's just sometimes isn't acceptable due to existing underground piping), but in some applications a VFD makes sense. Also you can't disregard the appetite some people have for technology and they like the simple intuitive display the VFD systems offer. I'm not saying that would matter to you or I, but it does matter to some.
In the case of the OP and the SCALA2, the main attraction may have been the advertised all-in-one nature of the SCALA2 product. While installing a CSV on a standard shallow well jet pump may seem easy to you or I, in reality it's not something everyone would describe as simple. Knowing how/where to install the CSV in relation to the pump and tank, moving the pressure switch (and the wiring involved in properly doing so), and then adjusting the pressure switch would be daunting to many homeowners whereas installing a SCALA2 is simple.
I do believe the SCALA2 will work for the OP, its just a matter of figuring out what problems he's having and helping him through the process.
Thank you very much! I couldn't agree more. There are lots of good applications for VFD's. The CSV only works with pumps in a certain range of flow and pressure, and with fairly cool and fairly clean water. However, that is about 95% of all water well and booster pump applications. The VFD is good on really deep wells, positive displacement pumps, and when pumping sewage, oil, blood platelets, etc. And yes VFD's have gotten a lot more dependable and less expensive. I can't argue with someone wanting to try new technology, I did the same thing. But the simpler the pump and controls the more likely water will squirt out of the faucet. And when there are two or more ways to accomplish the same task, as with a VFD or CSV, the simplest way is always best.
I really love VFD;s and pumps like the Scala. It gets people use to constant pressure and small pressure tanks. Then when they decide they want their constant pressure water supply to be dependable, I will still be here.