My experience of yellows was the same, initial bite is heavily sacrificed but yet I still overheated them too easily. The drop off in low temp/initial friction is so noticeable that even a slip road at the end of a motorway gives noticeable in stop mu rise that is akin to some seriously heavy duty track pads, yet without the benefit of heavy duty track pads. I found Axxis ultimates gave a much better initial bite and better high temp performance. They are much dustier though. Not sure if they still make them?You aren't wrong though. But I wonder, what the difference is between my brakes and other people who write comments such as "stock brakes are fine, just need better pads and fresh fluid"
I don't think my stock brakes are fine, I've put yellowstuff in and the initial bite feels terrible.
Failing that I quite like the PBS pads I tried on my EP3 so I'd be tempted by those? I currently have carbotech xp8's on the mx5 but I wouldn't recommend them for road or sprints; they have better initial bite than the yellows but their mu rise with temp is staggering and requires keeping them warm to make the most of them (e.g. great on track)