Uruguay weekend trip: Colonia and Montevideo

I’m going to Buenos Aires soon and planning a weekend trip to Uruguay. I’m 100% certain I’ll visit Colonia; the question is whether I will add Montevideo as well. I’m currently leaning towards doing so. my plan is as follows:

Saturday morning: ferry from Buenos Aires to Colonia, spend all day in Colonia and spend the night

sunday morning: bus to Montevideo from Colonia, spend day in Montevideo, spend the night

monday morning: take early ferry back to Buenos Aires from Montevideo

does this sound realistic? is it even worth going to Montevideo? I’ve heard mixed reviews, but I’m from very far away so I probably won’t have a chance to go back to Uruguay anytime soon. thanks in advance for any advice!