Is Cash on Cash the right metric for me?

[Martin DeBono]

I’m probably in the highest tax bracket in the country - high earner in California where my marginal rate is 50.3%.

I've been using CoC as the metric for my buy and hold investing.

I'm targeting 8% to 12% CoC.

My logic is that the cash I am getting is tax free so these returns are the equivalent of 16 to 24 percent pretax. I can also borrow so long as I put 25% down.

So - my strategy is that as long as I can borrow I should still invest in properties until my borrowing capacity is maxed out. Am I missing something?

Should I be looking at a different metric?

Thanks in advance