I just researched that issue. I will go with the .70 springs, but will add their emulators. There are some real good articles on these, and the full discussion and pics race tech web site make sense. The cost in minimal compared to a full suspension change, and, I don't need to make my KLR into my KX450F anyway!
I will get a .80 rear spring, as well and hope the shock adjustment will match the increased performance the fork springs, emulator and changed fork oil will give me. I will add a fork brace, as well. it's a 2012. If you find anything in your research that would be helpful, please post back.