The main concerns seem to be the cap on gains and the fees charged by insurance companies.

And that the indexed gains are the raw S&P index price, EXCLUDING dividends. That's huge. That's on the magnitude the old saw "Other than that, Mrs. Kennedy, how was the parade?"

Does anybody who is pushing these do anything as simple as looking at the historical prices? Stupid question--of course not. 'cause they'd see that from Mar 1987 to today, $100 in the S&P price-only grew to $436. But including dividends it grew to $813.

So, yeah, over the long haul the IUL company keeps a lot of your money. They keep so much that they can easily give you a meaningless guarantee.

Oh, and that $436 is BEFORE their various fees and caps. Not to mention the time-periods (frequency) in which they apply the cap.

Bah, all this has been hashed and re-hashed again and again. The phrase "willful blindness" comes to mind.
"It is difficult to get a man to understand something, when his salary depends upon his not understanding it!"