In my experience, as the inventor of Slicing Pie, many lawyers who are used to doing traditional splits get easily confused about Slicing Pie because they think of it as a variable compensation program that issues shares in lieu of cash. In their minds, this opens up a legal and tax can of worms.
Rest assured that ALL issues are easily addressed and you can find smart Slicing Pie lawyers and contract examples at http://slicingpie.com/slicing-pie-contracts-and-lawyers/
When you explain it, I find that a gambling analogy works well:
Think of the startup as a gamble. The winnings come in the form of profits or the proceeds of a sale. There is no way to know if you will win, when you will win or how much you will win. So, trying to split up the winnings (equity) based on future profits or value is pointless. The only thing you can actually know is what bets were placed.
When people contribute to a startup and don't get paid, they are betting the fair market value of their contribution on the future of the startup. Betting continues until the company reaches breakeven or Series A financing.
Slicing Pie bases the split on the bets placed, not on the future winnings. So, each person gets a share of equity that reflects their share of the bets.
Any other way of splitting equity is unfair and foolish.
LLCs provide flexibility in the allocation of profit and loss. C-Corps can issue restricted shares and use Slicing Pie as the vesting program upon termination. It's pretty straightforward.
If you have a lawyer who is willing to learn the model, put them in touch with me directly and I will walk them through the details and provide materials at no cost. They should not charge you for talking to me and learning the model because they can apply what they learn and make money with it. There are entire law firms who focus on Slicing Pie deals.
If you use this analogy and they still cross their eyes you may have to find another lawyer!
That second part especially seems to be a bit easier to grasp for some lawyers.