One of my MBB instructors in Six Sigma (a long time Kodak statistician) told us that you could analyze anything with regression that you could with ANOVA plus a lot more that you cannot do in ANOVA. I have been able to duplicate any ANOVA that I have done using regression, so it typically boils down to preference and which has the better output from the software. For Repeated Measures studies, I have to use GLM (which uses regression behind the curtain) as Minitab does not have an RM-ANOVA.