After reading your post, and the replies thus far, put me in the, "its better to have diversity" camp.
You just never know what little surprise might blindside a large holding.
I really do like EPD as a long term holding though.
I also like WPZ...after their announcement a couple of weeks back about restructuring, and listening in on the CC, I feel really good about them for the next two years. Good DCF growth expected and "blessed" with growth opportunities.
And, I also like NRGP...it's residential propane business is a cash cow, and they are growing in the midstream pipeline and NG storage area. They also own a company that extracts salt from underground mines...leaving salt cavities for further expansion of their NG storage capacities.
I first agree the EPD is actually fairly well diversified, however, a group of MLPs certainly makes sense and does offer additional protection to stabilize a return. As was already stated TurboTax does my 10 MLPs just fine.
You mention diversifying to get a higher yield. A couple thoughts here. First is Factoids CAGR. Howfast is the distribution growing. Does no good to buy a MLP with a 2% higher yield if they do not grow their distribution, does it? A slower steady grower might in the longer term provide better growth.
Second is that distribution yields generally equate a balance between future growth and risk. Those MLPs with higher yields are either perceived as having less growth potential, have a riskier business, or are weaker financially. Thus the E & P sector has high yields due to risk and some of the smaller MLPs higher ones due to lack of financial strength.
EPD is my core holding and the one I bought first. Adding additional MLPs now might be a good plan.
If you watch much CNBC you hear the talking heads going on and on about AAPL....it is a wonderful company, no doubt. But check out the last year of AAPL vs NRGP (or vs the S&P 500)....guess who wins that race (not even including the distribution of NRGP: