Well for myself it wasn't one of the more successful antipsychotics as it was activating and kept me up at night and caused heart palpatations so I had to discontinue it (with supervision). Other people do find it works though and its less likely to cause weight gain than other antipsychotics but can often be activating so if that's a problem you can ask your psychiatrist if you can take it in the morning.
It worked great for me and alleviated all my psychosis at the right dosage and got rid of all but one of my negative symptoms but it caused me to have bad memory loss sometimes and some days I felt stupid on it. It also reduced some of my personality traits. I noticed a change immediately but this is different for everyone I think. I also had heart problems like ILADVOCATE where it felt like my heart was being ripped apart and I had to stop taking it as well.
Geodon also even got rid of my crippling depression that I couldn't move from at times and I didn't need an antidepressant at all.