Hi KCallie,
I like the smoother ride offered by CAIBX as well as its almost predictable consistency in frothy market conditions. AMECX has a higher yield because it has a greater exposure to junk bonds than CAIBX. It is a tad more aggressive as well. One can still sleep well with it anyhow.
That being said, I when I get to retirement would actually use a combo of both funds (hopefully they still exist then and their mandate remains the same!) as I like AMECX.
You can't go wrong with either fund!
I don't know whether you have any but consider adding a slug of the Capital World Bond fund (about 5-7%) to juice things up a little bit. It is nice relatively conservative approach to dabbling in world bond market issues. Its five percent yield does not hurt either.
Check this chart out...(Disclosure: I own some Wellington as a core fund as well as CAIBX..I don't think the chart takes into consideration Cap gains and divvys but it still presents a nice snapshot view of the funds)
http://finance.yahoo.com/q/bc?t=my&s=AMECX&l=on&z=m&q=l&c=vwelx%2Ccaibx%2Ccwbfx
Wayne.