I don't think conversion to either BA or AA is worthwhile if you have E or SE with AC.
I am SE with AC. I still love to convert RBC points to BA points. I can get one-way CX tickets in F with multiple stopovers.
I even collect Esso points instead of AP miles at Esso gas stations. Esso points can be converted to RBC points and in turn converted to BA miles, at a much more favorable rate than the stupid 3 AP per dollar rate.