I've had it running 8h+ of non-stop optimizations, chasing a performance target, rewriting systems or building a series of prototypes for research. All it needs is a clear goal.
There needs to be a mode where it's "don't change code, don't lock in decisions, lets explore", and the problem with plan mode is that it all of a sudden presents a too-long, multi-screen plan that's just completely off base with basically two options: "go and do it all" or "tell me what's wrong and then I'll make a small modification on two screenfulls of text and not tell you what I changed."
If it works for you, great, but Claude was far better for me before 5. it got slightly better with 5.5, but the harness deteriorates every days as programmers try to gain internal clout by shoving in poor features.
Pi is such a relief in comparison to Claude, those who can use it really should.