"Better" depends on what you care about. _konniti-wa_ (which is the Kunrei-siki romanization of こんにちは, _konniti-ha_ is Nihon-shiki form that preserves the irregular use of は as topic-marking /wa/) and _susi-o_ (again, Kunrei-siki ignores a native script orthographic irregularity and romanizes を as _o_ not _wo_ ) are more consistent with the native phonological system of Japanese. In Japanese coronal consonants like /t/ and /s/ are regularly palatalized to /tS/ and /S/ before the vowel /i/, and there's no reason to treat _chi_ and _ti_ as meaningfully different sequences of sounds. Linguists writing about Japanese phonology use it instead of Hepburn for good reason.

Obviously, being more transparent to English-readers is also a reasonable goal a romanization system might have, and if that's your goal the Hepburn is a better system. I don't have a strong opinion about which system the Japanese government should treat as official, and realistically neither one is going to go away. But it's simply not the case that Hepburn is a better romanization scheme for every purpose.