I too have studied and practiced nikko style putting quite a bit. I spent about a month working on it in my house while I was snowed in this winter. I think that nikko is probably the best putter in disc golf, but his style is also one of the most physically demanding. Because the weight transfer is so dramatic it requires a lot of core strength and above all control of your balance. Once I learned nikko's straight arm swing I found it incredibly easy to throw a putter on a hard, direct line. But everytime I missed it was because I wasn't in control of my balance. My typical mistake with the nikko putt is to miss right, because of the left to right swing of the back leg. I don't rotate enough and release early. Ultimately the variability of that left to right body rotation before release is what made me go back to spin putting.
I think the biggest advantage of Doss/Anthon style spin putting is that you can use a very easy comfortable stance. Your stance is almost always the same on flat ground and your feet don't have to be very wide apart. And since you are putting from the chest, when your stance has to be modified due to obstacles, your putting motion from the waist up doesn't have to change at all. Nikko swings his arm so dramatically that when he has to modify his stance, he always has to figure out a way to get his legs out of the way of his arm on that low swing. That's way you can observe him putting with 3 or 4 distinctly different styles in the same round, although the fundamental motion (low to high straight arm swing) remains the same.
The drawback of spin putting of course is that it's all in the wrist. Your release has to be consistent every time. I think it's easier to not be in the zone with spin putting because a relatively small error in your wrist or hand leads to a miss. With nikko's putt, a consistent release is almost a given since the straight arm swing determines the line the disc will fly on. His is a more athletic or physically demanding putt, but since you can draw a very big line with your full arm swing I think it's easier to aim.
Since Nikko's putt is so extreme and he's pretty much the only person I've ever seen putt that way, it's safe to assume that the putting style you finally decide on will be somewhere in between his straight arm putt and a spin putt. The best advice I think anyone can give on putting is to just focus on a consistent release and practice practice practice that wrist motion. If the release becomes second nature then your stance, distance, etc. shouldn't really come into play. As long as you can visualize the putt going in and your consistent release has become second nature, your body will know how to make it go in.