Do you want the *BEST*? Felix is it, IMO.
But I don't have a ton of experience with much else in the same category. I did use an AI Flex for a few years before the Felix. Felix is significantly better, IMO. I've messed with the Headway and didn't care much for it at the time. That was a long time ago. Felix just fits my needs, so I stick with it. Think of it as 2 studio-grade channel strips in a pedal. It has a TON of routing features that you may or may not need, but at the core, it's 2 independent mic preamps/EQs/DIs in a pedal. Perhaps a downside is that there isn't much color, if you're looking for that. It's clean, clear, pristine, etc., but not a lot of mojo by itself. You can always stick some mojo in the insert, if you're looking for that. But again, the routing is so flexible that you could have your mojo-box in the insert for a pickup going to FOH and your amp, and still pass your mic straight to FOH without the mojo-box touching it. Perhaps the only other routing gripe is that you can't route both inputs to either channel (that I've figured out - yet). That means you can't use the same source for the 2 channels with different settings. I believe you can run a TRS into input 2 and have the ring route to CH1, so you could make a custom TS>TRS cable to route a single source to both channels. I may try that.
If you don't need 2 channels, the Alix would be great, too. Also, I haven't used the Felix2, so my experience is based on the first gen Felix.