@Greengenes707 you are right, my heatsink looks different than cooliance. Just like you said... the thermal resistance is about the same.
I have tried heatsinks with thinner and more number of pins, looks like thinner pins are more suited if pin height is less.
Also for DIY it seems thicker pins are better as they do not bend easily, which is a concern while shipping.
A lot of focus is given to the surface area and not so much with how the heatsinks pull air streams for convection cooling. Unlike Flat heatsinks, pin heatsinks pull air from 360 degrees and creates airstreams and thus offers much better cooling. I am sure you already know. This article explains a little better if anyone is interested.
http://www.newelectronics.co.uk/electronics-technology/pin-fin-heat-sinks-point-the-way-to-more-efficient-cooling/18641/
Here is my private collection
The one in the center is the one i sell and its the best of the group. Anodized were better at cooling. Round pins better than line shaped pins. Base thickness is important. too many pins (square in photo) and very closely packed did not perform as good. top right is serrated pins, slightly better than flat but pin hs beats all.
Most of my data was measured with a 25 watt power resistor. Those large extruded profiles on top were reaching 50+ C and pins HS weight much less and were in mid 40's for small once and low 40's C for large once.
Tested some exotic copper and splayed pin designs but they are expensive, not easy to work with and ship. They do have slightly better performance but for same price I could get a bigger/better performance heatsink with regular aluminum pin style.