I got into this though the consolidation w/ MMG which I picked up very cheap last winter. It has been a good one to own but it has appreciated to a point where the yield is kind of h-hum when compared to other MLPs. This has been happening to various degrees with other pipeline MLPs some of which I have parted with as well. Some of the yields have fallen to a point where you have to question how much more upside will there be without distribution growth. I am finding much higher distributions in other MLPs and even some telecom and utility stocks which offer some higher probability of capital appreciation. Anyway, nothing wrong with this at all but looking to move into other areas in the market. Good luck to you all.
Suppose I bought MMP a year ago when it was yielding 12%. The price has since doubled so the current yield is 6%. Now, as you point out, the yield on my original investment is still 12%, but if I sell my units and invest in another MLP that is currently yielding 8%, I will now be making 16% on my original investment, ignoring taxes*. You can't look backwards on investments, only forward.
*Of course you can't ignore taxes. Decisions in the real world may be very different than they would be in a tax-free world.
I'm taking the other side which is the elimination of the GP could increase the distribution rate longer term.
This year, I would expect a lower distribution rate increase assuming the absorption of the GP was slightly dilutive in the near term.
Unfortunately, MMP is sort of the it stock in the oil space w/ access to 43% of all refining capacity in the U.S. Buckeye is good but is slow as molasis in the growth area and I do want some exposure to oil.