The Smooth S Shape is your best possible choice--hands down.
It is perfectly designed for G-spot (or even P-spot) stimulation, not just on one end but on both ends.
I have six NobEssence toys. I love them all because of their carefully designed shapes that are perfect for G-spot stimulation. However, as much as I love all six of my NobEssence toys, I love the Smooth S Shape the best. It truly is pure perfection.
I just want to emphasize that it is the unique shape of NobEssence toys that makes them so effective; it is the fantastic, incredible, carefully rendered shapes that impart the most incredible sensations and make this line special.
Sure, the firmness of the wood has a lot to do with how wonderful these shapes feel, and it is also nice that wood is not as heavy as other hard materials would be in such a substantial size (many of NobEssence's toys are quite large since many are double-ended; a metal or glass toy of the same size and shape would be prohibitively heavy for many--though, of course, not all--people).
Given that NobEssence has such unique shapes and provide such a unique feel, I don't think you would be able to determine whether you would like a NobEssence toy simply by trying a wood toy from another company.