PP here, you can also look this up on a variety of calculators, but in general without a COL adjustment that argues for lump sum, which also can be left to spouse (or children--which cannot generally receive a pension). you also need to see if the amount you receive shifts if you choose survivor benefits.
spouse and I both have pensions. Both have COL adjustments as well. We are keeping his with survivor benefits (its like 5k month) and I am cashing out mine. (1200 month if we took it). I do not think the small monthly amount will really shift things in our case--we have enough money saved elsewhere and also his pension functions as our guaranteed income/bond-type asset. I'd much rather invest the money I will have when I retire, esp as I can't really see needing that monthly income. It will hopefuly grow and my kids will inherit it at a step up basis.