Over on the main Lease then Buyout thread
Lease then Buyout - Contract Explanation you'll read a lot of discussion about if the buyout process is worth the hassle. My experience then would be different than now (after getting educated on that thread

); that thread convinced me to do the buyout c. three months into the lease.
Knowing what I do now, I would not have done the lease then buyout, because if I had known what I found out later, I'd have just paid cash and negotiated as much direct dealer discount as I could get.
They opened negotiations with a straight up $2,995 off MSRP. We offered to pay cash and were shocked to find out that their discount would only be an additional $500; they wouldn't budge on that. Kia's finance incentive was just under a thousand bucks. But I don't think that we would have obtained that without going through the financing process. Our intentions were clear: pay cash. So getting the c. $950 Kia finance incentive would have been problematic.
If you look at the pluses and minuses, I don't think that anything beats paying cash. The lease rebate is for people who can't pay cash (i.e. nearly every prospective car buyer).
So, negotiate out the door via dealer discount; forget Kia's rebates entirely. If the out the door price fits your definition of a good deal, just do that; it's relatively simple and painless.