I've tested EDGE, ENT, and DRIVE wheels. The ENT and EDGE differ mainly in weight, spokes, and rim profiles. I am not sure about the SLT and SLR. I will consider writing a comparison article about all these wheelsets. Anyway, the DRIVE wheels have carbon spokes and ceramic bearings.
Regarding ride feel, EDGE + ENT are pretty soft but comfortable. But for example, I didn't feel like riding 1350g wheels when riding EDGE. They are not as responsive as DRIVE ones, which are a bit lighter. The ENTs are much heavier and better for flats and steady efforts.
Having said that, I would recommend saving a bit more for DRIVE wheels. They are my go-to climbing wheels (45mm depth weighs under 1300g), and they are much more responsive than EDGE.
However, it also depends on your experience. For example, I would be happy if I was transitioning from ALU wheels to EDGE. But given that I've tried wheels costing over $1000 with carbon spokes, I'd opt for those instead.
Feel free to visit my website where you learn more details on these wheels.