You get slightly more bang for your buck with the RUT "classic" due its higher implied volatility (there isn't a July 8th expiry yet, so the comparison isn't quite precise); you get $355 for a $10 wide with a $645 buying power effect:
At some point, you have to transition to these larger instruments over things like IWM, QQQ, and SPY unless you want to just keep increasing the number of contracts you use (which result in higher fees/commissions). Widening the wings in a SPY IC to scale the trade to your account/risk tolerance to get more "bang" only goes so far, since the long options start to get "too cheap" the wider you go with your spreads and/or wings, making the exit from a wing for which the long option has gone "no bid" a hassle (you basically have to exit the short option first and allow the long to expire worthless).
At some point, you have to transition to these larger instruments over things like IWM, QQQ, and SPY unless you want to just keep increasing the number of contracts you use (which result in higher fees/commissions). Widening the wings in a SPY IC to scale the trade to your account/risk tolerance to get more "bang" only goes so far, since the long options start to get "too cheap" the wider you go with your spreads and/or wings, making the exit from a wing for which the long option has gone "no bid" a hassle (you basically have to exit the short option first and allow the long to expire worthless).
Fireworks are fun ... as long as you don't blow your fingers off.