EB is far more complex than vanilla RTW and it is simply slower than RTW vanilla. Its got nothing to do with your installation sequence, I have the same (RTW1.0 -> RTW-BI 1.3 -) RTW-BI 1.6 -> RTW-BI 1.6 + EB) and 0.8 runs as good, but probably better than EB 0.74 did.