Yes, the level premiums of whole life make those policies more expensive in the early years, while the fact that universal life gets more expensive later on means you'll want to max out your contributions in the early years. Some folks prefer whole life for its predictability, while others prefer universal life for its flexibility and the chance to amass a larger cash value. The way I see it, it comes down to knowing what you want and what you're comfortable with.
I do like IULs. Out of curiosity, who's the insurance company behind your IUL? And what type of indexed account are you investing in? One that's tied to a single index like the S&P 500, or one that's tied to multiple indices?
Life Insurance of SouthWest National Life Group. I am using S&P500 index but you can change to whatever you want (Fixed, S&P Indexed or MSCI Index) S&P has done just fine :).
Yes, every IUL I've seen offers at minimum a fixed account and an S&P 500-indexed account, and most people I know who invest in the latter type of account have been happy with it. Some IULs offer a more convoluted type of indexed account that, each month, compares the results of three different indices (like S&P 500, EuroStoxx 50, & Hang Seng) over the preceding 12 months and credits you a weighted average of the three (weighted based on how each index performed over the look-back period). But that means less transparency than a simple S&P 500-indexed account, and some people don't like that.