Regarding Leveraged ETFs

I am a skeptic on leveraged ETFs in one way.  My view is that the more levered they get, the less likely they are to replicate the behavior of their index, however levered.

To get high amounts of leverage, they must rely on futures, options, swaps, and options on swaps, and the higher the amount of leverage they attempt to replicate, the greater the amount of slippage they will experience versus their multiplied index.  There is also slippage from rolling futures from month to month.

Here’s my challenge, and I may do this myself, or, though I encourage others to do it.  Add the performance of the bullish and bearish funds of an index together, for a given amount of leverage.  If there is no friction or fees, they should do as well as T-bills.  My guess is the higher the leverage the lower the aggregate returns.

Let the games begin.  Does anyone want to run this analysis before I do it, say, six months from now?