Je trouve que c’est celui qui a le moins changé… is by far the more natural way to state it.

Je trouve qu’il est celui qui a le moins changé…, while not being grammatically incorrect, is unnatural and would likely be avoided in a casual conversation by a native French speaker for being too emphatic. Paradoxically, that form is much more likely to be used by non native French speakers because, as you wrote, many are reluctant to use ce to refer to people.

For example, Ils sont français is fine but Ils sont des Français, while fully understandable is very unidiomatic. All native will correct it to Ce sont des Français.