Tax Free growth (If you don't sell you're never taxed, just like an IUL)
Tax free distribution (take a margin loan that's even tax deductible, unlike the loan from an IUL)
Liquidity (it's highly liquid)
No contribution limits

Now add on top:

Uncapped Growth
The 10% bump you're not having to pay as commission to the agent who sold it
The high mortality costs you would be paying for the underlying permanent insurance you may not need past age 65 or so
Lower capital gains tax rates if you do sell verses the ordinary income in IULs