I can't say "as a whole" which one I liked better because each had useful party members and each had useless (IMO) party members.
Loved:
K1- Bastila, Jolee, HK-47, Canderous
K2- Kreia (best character of both games, IMO), Mira, Atton, Handmaiden, Visas
Liked:
K1- Carth, Juhani, Mission
K2- T3, HK-47, Disciple, Hanharr, Bao-Dur
Disliked:
K1- T3, Zaalbar
K2- Mandalore, GoTo (liked his backstory, didn't like him as a party member)
Overall, I felt that the K2 characters were deeper, and there were less useless characters. Although I didn't like GoTo in my party of 3, I thought his backstory made him interesting. Which left only Mandalore from my K2 party that I didn't like, and that was mainly because we already knew his backstory from K1.