canyoneagle, I don't know if there are any new aluminum handlebars without channels. Modolo has a set of steel bars without them, however.

Handlebars that I've found comfortable: I have a set of Cinelli 64s, shallow reach and shallow-medium drop make them very adaptable to most riding styles. For my long distance road bike I installed a set of Modolo Q-Race ergo bars. They're not radically ergo with a medium reach and drop. My rat bike has a set of North Star 'bars that are similar to the Q-Race and the budget king of good 'bars. The touring bike is using the 'bars I removed from the long distance road bike (to try the Modolos). While they're CODA bars the brand isn't important, but the medium reach to drop ratio is almost square (the same) making for a good neutral fitting 'bar on tops, drops and hoods.

Good luck with your search as handlebars are such a personal fit item.

Brad

PS I removed a set of Modolo Brevettato 'bars from the touring bike because they were too narrow for me, but their ergos are similar to the Cinelli 64 'bars.