Call writing has become a fad that may soon turn into a mania. Not saying it is some kind of evil force, just that no one knows how it will play out in the long run, generally, or how individual funds may profit or lose with it.
CEFs I've invested in beginning in 2001, mainly for income (I'm retired) and have been pleased with are: ACG, AWF, IGD, CWF, EAD, ESD, FAX, HTR, HYF, RIT. Some others I'm less pleased with I will not list here, but I still own them for the income. I also own two Canroys for income: ERF and PWE. I bought these Canroys when they were cheap, so even though their prices were crushed in the last 12 months I can still hold them without pain. A new (to me) CEF I'm looking to buy is HIX. As in any investment, whether for income or gain, what matters more than any other consideration is the price you pay. Last Sept. and Oct. (and again in Feb.) I fattened my income portfolio when prices fell into a cave, in some cases landing yields above 20% (IGD and EAD).