There are some beautiful Cracks in here. I have two myself. One with Speedball, the other without. I attempted to apply a finish to the wood, but since I'm a n00b at coating wood, I choose not to attempt it on the Mainline. The Cracks are simple and fun builds, and the cost (especially during the sales) is well beyond respectable for the performance.
I find the perfect marriage is when they are used with the Sennheiser HD650. I have listened to AKG K702/Q701, DT770 (250ohm), DT880 (250ohm), and several other headphones, but I usually end up going back to the HD650s.