+1 on that.  Curvetines also do NOT require a seed firmer to get seed/soil contact. You can use a seed firmer if you wish but one is not required as it is with some straight, pointed spike tooth closers.

The Curvetines work very differently than a straight, pointed, spike tooth closer.  I think of the way the Curvetine works as being like the way I plant sweet corn in the garden by hand. Planting sweet corn in the garden I poke each seed into the soil down to my second knuckle with my index finger which provides good seed to soil contact at the bottom of the seed slot.  The wide tip of the Curvetine wheel does the same but at row crop planter speeds.

In many soils, leaving the surface a bit pock marked behind the planter (but seed at constant depth and in good seed/soil contact) greatly reduces crusting-related emergence problems.

Jim at Dawn