I don't like that they replaced Jool with Sikozu, just when I was starting to like Jool.
I totally agree. In my opinion Sikozu never was a well-defined character. Often times her loyalties and decisions felt out of place. All the stuff about the resistance, her relationship with Scorpius, her actions in The Peacekeeper Wars etc. Very odd to say the least. Not to mention she was incredibly annoying with all her arrogance, even more so than Jool ever was.
Sikozu is one of the very
few fictional characters I genuinely loathe (Byron from B5 is the only other one I can think of, in fact). Rightly or wrongly, I tend to think of Jool as a second-rate Zhaan; Sikozu I think of as a 50th-rate Jool. Rewatching the fourth season is a struggle for me simply because she's in it.