Im not fully knowledgeable of everything in C4D regarding Uv mapping so I could only tell you what I find about Unfold3d in how easy and fast for me, maybe you could make a comparison off that.
First off seam selection is very easy, not just loops, but automatic path between two edges is quite intelligent in picking the best path. I can work in full symmetry as you would expect with options to increase tolerance, and working of different planes. Once iv cut the seams, and press unfold, its about 90% done, and with a host of relax methods its easy to get the distortions out while viewing a heat map that indicates distortion. It has automatic pinning by which I can select polys, edges, or verts individually looped selected or individual. Within a few seconds iv pinned say between the fingers, and have moved them to get any overlaps dealt with. The new version of unfold which I dont have automatically sorts overlapping Uvs. The Islands can be selected with a dedicated gizmo to scale, move, rotate which will also work on the symmetrically opposite at the same time.
I can paint areas that can be used to give more priority to for Uv space such as the face. I can select a strip such as in this project the gums, and can flatten out the U and V rows in one single click. I can also do mapping which stretch the head for instance to the shape of the Uv square space to get every bit of uv space used. I can select one single nail, and have any duplicates also selected and stacked on top of each other. It supports UDIMS space and can automatically fit all parts across as many Udims as you choose. These are the main things that come to mind, but there are plenty more things that I may take for granted. The new version which is v9 has tons more features, im 4 years behind.
Dan