If you end up thinking it's the hydraulics, you can diagnose it further by draining the brake fluid and replacing it with SAE 0W20 full synthetic motor oil.
Use a synthetic because a mineral oil will cause the seals to swell. (Not that there are mineral oil 0W20 oils anyway.) If the "feel" is better and it works like it should, then either you were low on fluid before, or the fluid was leaking past the seals of the slave cylinder. The 0W20 is thicker (higher viscosity) than brake fluid and leaks less.
I had a "failing" clutch system and first replaced the fluid with an aircraft hydraulic fluid. I also put a gasket from an earlier clutch system in a jar, along with the aircraft hydraulic fluid. After a few days the gasket was noticeably larger (and softer.) I frantically replaced the hydraulic fluid with the engine oil, then after another week, flushed with more engine oil. It has cured the original problem and I haven't had any leak or problem since. Of course, my experiment gone wild could fail tomorrow because the seals have been softened too much (but this was several years ago.)
If the 0W20 works for you, great. I would give it a month and flush back to brake fluid. It you want to take a risk (my experiment is one of one, so 100% success, but no repeatability or reproducibility) you could leave the 0W20 oil in the system. If it fails, you were looking at replacing it anyway, as those are classic symptoms.
