Lamictal has a reputation for helping a little for the depressive phase of the cycle in addition to its stabilising properties. I can't comment on Geodon though.
There is a small chance of you developing a rash with Lamictal, usually relatively early on in your taking it. It can potentially develop into a very serious rash, so report any outbreak of rashes to your pdoc immediately.

I've been on Lamictin 200mg (identical to Lamictal) for a year, along with Epilim 800mg.
These have been the least distressing drugs for me so far, over the last 3 years.

I haven't had a full duration manic episode since I have been on them, or a long depressive episode either. Maybe they are doing something right.
However, I have not stopped ultra rapid cycling with mixed, manic, suicidal, paranoid and perceptual problems spiking out every month or so from my regular moderate weekly cycle.

So for me they are probably not doing a strong enough job, and we are considering putting me back onto antipsychotics to tighten things up a bit.

The outlook for bipolar II is probably a whole lot better on those meds than has been my experience.

I hope you soon find the right treatment to make life a whole lot more manageable.
Take care.
TS