Haven't tried other similar instruments like Russell 2000 etc., but in my experience chances are that it will work even worse as even the slightest difference in characteristics often has a negative impact, anyway might be worth trying...
Russell 2k has a fairly high correlation to ES nowadays, I think you would end up simply with higher returns coupled with equally higher drawdowns. Your best bet is to trade futures from a different country or going with something like an emerging markets ETF (much lower correlation as compared to Russell 2k). I won't mention something like energies as your edge in those probably won't work.
