Here's an idea: Keep the ZXL in the line-up, and see how many Circa rods sell. They do this to stay in business. They don't make payroll with the rods already sold, so they have to offer new and improved rods to keep sales going. New and improved allows them to bump the price up: it's new and improved, so of course it costs more. I might have enough rods to last me the next couple of decades, so go ahead and buy the new Sage rods. I might need the company to be there if one of my current rods needs waranty work.
We just bought a new Jeep, so buy their products as well (for the same reason

).
Honestly, I've really enjoyed buying a few premium rods. The 486 ZXL and 590 Z-Axis cover any situation I find myself in. The 4wt ZXL will cast a 1/40 oz Clouser with acceptable results, and really loves to cast dry flies. Accuracy and presentation are better than I ever hoped for, and I'm not interested in the next sales pitch. The ZXL is plenty slow, and the Z-Axis is plenty fast. I bought these rods when they were first made available, and we've grown accustomed to each other. Why would I want to change that? To keep Sage afloat? That's their problem. They chose to get into a market that isn't too unlike the hammer business. I worked in home improvements for nearly two decades, and owned maybe 3 16oz hammers. Those companies stay in business because hammers get lost, or abused to the point where you might want one that doesn't look like it was used to batter concrete walls down. Most of their sales are from people that just need a hammer for around the house, and all you have to do is hang some on display at the store. Of course people don't need a fly rod to have around the house
Did Sage produce a rod that is lighter, and allows
you to cast further than
you were able with your previous gear? If so, and you want to buy another, more power to you and Sage. It's not my place to tell them what to make, nor tell you what to buy. I won't be buying any new rods from anyone, unless the rods I own now get lost. Even then, I want something that isn't too far different than what I already own.