I'll chime in a few opinions and one experience with the L1:
1. Saw the COR come out, disappointed in the size of the biggest one (nothing as strong as the L1, bummer). Cool that you can monitor the current and set the min flow to prevent back siphoning.
2. The Vectra calibration function is pretty awesome setting max speed and min speed, allows you to keep from back-siphoning just like the COR can do.
3. My L1 failed once, the inside melted, bubbled, interfered with the impeller, and locked up. Ecotech was great and overnighted me a new one, but still, I have heard of this from several parties now and it has me worried about sticking with these long term. However, the replacement pump is going strong now several months later.
4. Abyzz and Red Dragon are still a lot of money.
I find that not being able to control the return with the Apex is not a huge deal. I can turn it on and off, and I only turn it up or down during water changes.
We are contemplating an upgrade soon and I am leaning toward an RD3 150W or two.