I was considering getting a Surly Cog for a SS build I am doing. However, my bike is a conversion with a cassette hub. Will I encounter the same problems with a cassette cog as well?
I also saw some pretty cheap cogs from Dimension but initially dismissed them because they looked liked they were stamped from thin guage sheet metal. But if Surly which is a solid machine milled cog is so bad, maybe a stamped cog would be better. Any opinons?

Surly cog: $30
Dimension Cog: $3.50