1. Potential ban due to ToS violation;
2. It doesn't follow all Anthropic's communication mechanisms out-of-the-box, they heavily use custom headers, hidden flags, and undocumented API features that affect models' behavior;
3. Compact is better in CC (significantly);
4. Cache related nuances (I mean, A\ regularly messes up with cache even in CC, their caching is non-trivial);
5. It's almost unavoidable to use Pi's extensions, and I wouldn't trust my oauth token to anything third-party (take a look at regular reddit/X posts where people getting banned due to such leaks and abuse) -> it takes enormous amount of hacking on top of Pi to get closer to CC abilities.
CC has hooks and mods, even ui_* (undocumented) protocol if you need some big customization, those are enough to implement whatever you want on top of CC.
Also, I'm working with CC from the very first versions, as for me - it's the best harness (as-is) on the market. I have zero clue what problems people are talking about (except known big issues, 3-4 over the years, I've never had serious problems, at all). Seamless and smooth experience, optimized for Anthropic models.
P.S. You can consider this as Stockholm syndrome effect, but... you have close to zero chances to get unbanned with Anthropic, and it's the best coding model(s) available today.