On Monday we aerified all the greens with knife style tines. The tines are about 3/4" wide and a good 1/4" thick, they go about 3-4" deep. This has been the normal practice for the last couple of years in the spring. It is a low impact type of aerifying and just creates air chambers without pulling out the soil/organic matter. Our greens have a pretty good rootzone mix of sand/soil from years of topdressing, and the organic matter is not too built up. This allows us to not take cores twice a year, but rather use something that is less obstructive to the playing surface. However, if I thought coring was waranted for the spring aerifying I would not hesitate to do it.
On the same note, we did core aerify the collars of all 18 greens on Tuesday. The timing could not have been better with the 1/2" of rain we received almost immediately after finishing the last green. We aerified, picked up the cores, topdressed with a sand/soil/peat mix, seeded with bentgrass, and dragged it all in. The rain was perfect for soaking the seed and "melting" the topdressing into the turf. We may also do this routine on some of the worst areas in the rough that just don't seem to want to fill in. For the few burned out fairway spots (#10 comes to mind) we will be slit seeding and topdressing those sometime this week.