I find eps. like "Code of Honor" & "Up The Long Ladder" which are culturally and racially more offensive than "Threshold". However, it's interesting that "The Fly" was his original inspiration. I always thought it was "Altered States".
I think Seven was a great addition to Voyager and to Trek in general.
I think Kes was to stoic of a character to stand out against a group of characters that had far more colorful personalities than she did.
Seven was very vocal and brought back much of the inner tension the show required.
I like that Kim stayed over Kes too.
Kim provided lots of great moments between him and Tom, B'Elanna & Seven. Harry was such a dork he made them all look cooler in comparison. I can't recall any moments between Kes & B'Elanna at all.
Plus, I think it was a more PC move to keep the only Asian actor to be in the main cast of Trek and less controversial to swap out one blonde blue eyed female character for another.
Keeping an Asian actor also keeps within Treks theme of showing diversity.