So the latest incarnation of IBM's Enterprise Software and Services Offerings (ESSO) takes the form of precious stones ... hard to argue, it can offer good value when put to good use. But that means knowing how to get the most out of the ACP and CBA, and also S&S Credits where you can. If you've loaded up your MLC projections make sure you don't lose that value either, I'd recommend preparing for renewal up to 12 months before expiry - you want to establish your baseline before IBM does, as it's pretty much locked in at that point. It takes effort, but it'll be worth it.
If you (a) start with the wrong baseline (and to IBM that's your S&S at the time, whether you're going to renew it or not), or (b) just take a guess at your future MLC, you could forfeit major, not minor, MAJOR dollars. Get ahead of the curve, sort your position out early. Only then can you negotiate on your terms.