But "good" area is really quite subjective. It depends on if you like tract houses or not, McMansions or not, homes with a lot of land like mine, or new homes, etc. I could certainly tell you some areas of Simi to avoid, if you want to email me privately, but I will not post it in an open forum, because I would not want to offend anyone who might live in or near those areas.
I think there are a lot of neighborhoods throughout Simi that would be great - depends on if you like older homes w/more of a lot or a newer home w/smaller lots. There is a whole new development up off of Erringer that have larger homes and were built w/in the last couple of years. There are older developments too that are really nice - Texas Track, Indian Hills, Hollow Hills (that is where we are - house is going on the market if you are interested; 3bd 2bath - nice sized lot w/RV).
You can't do wrong w/Simi - I think it is much better than anything you will find in the valley! Quieter area and still has some small town feel!
Good luck w/your move!