|Speaking of ROC, not all ROC is destructive.|
One of the simplest ways to know if a fund is utilizing destructive or constructive ROC is to watch its NAV. A growing NAV over a period of time indicates that the fund is earning its distribution. An eroding NAV will indicate that they really are merely returning your investment to you, without earning these through unrealized gains or elsewhere. An eroding NAV isn't a sustainable long-term investment and an investor will eventually see distribution cuts.
In a taxable account, ROC with a rising NAV can be beneficial in tax planning.
I'd have to look at the funds to see which ones pay ROC while increasing NAV, but BST is one. BSTZ, EOI, EOS and THQ are just a few I can think of off the top of my head. In fact, I added to THQ today.
The tax benefits from ROC being utilized in a portion of the distribution stems primarily from MLP holdings and option based CEFs. ROC reduces an investor's cost basis on the original share price purchased. This defers taxes for an investor until they sell the shares. When an investor sells the shares, it is then taxed at a capital gains rate, which is also beneficial. If a CEF is held long enough, an investor's cost basis will be reduced to $0. When this occurs any subsequent payment from ROC will be taxed at a capital gains rate.