[Slick]

Is SEV (as it is now) in your opinion better than SEIV?

Much worse.




Does it have any major bug which render it quite unplayable?

Yes, too many to list. Additionally, the UI is extremely cumbersome and this alone makes the game very unfun.



How is performing AI? Is it better, out of the box, than SEIV?

Tough to say since both are very poor.



And using player mod is AI competitive enough and enjoyable?

At least SE4 had mods such as TDM Modpack to make the AI more challenging. I'm hoping that those guys are working on something similar for SE5, but it isn't out yet. There is a balance mod out, by Kwok, that does help the AI, though not specifically designed to do that. The AI's are hurt both by not being very good to start with and also by some of the the same bugs that affect human players (such as certain things not working).