VPI Steel vs. Aluminium tonearm

I just ordered a Classic with the periphery ring, clamp, and Nordost wiring to replace my Rega P5. I am wondering if I should have ordered the table with the stainless steel arm vs. the aluminum arm. I am currently using a Benz Glider SL, but I am planning on going with a Lyra Skala, or a Benz LP in the near future. What are the advantages or disadvantages to either arm?

Thanks for you help!