I know that several people are making lowering links, some use 6061 and others use 7075. Both saying the others are not as good and so on.

Anyone ever had a problem with either type?

I've had two sets from Brocks on two different bikes and never a problem from either. Not sure what material he is using, but they are good for me.

i have never seen any break
we use flat stock from the
local hardware store must of
the time just my two cents.

I had some break out of alumina don't know what type tho, starting useing steel afterwards and never had a problem since