I dont know where to begin ...
If you want a Miami like atmosphere, then please try Punta del Este. The beaches are world class but remember that February is high season in Uruguay and is visited by nearly 3,000,000 Argentines ... Sometimes there are more Argentines on the streets of Uruguayan cities than Uruguayans.
Montevideo is great at any time during the year. I would recommend the historic Ciudad Vieja, the part of the city that is nearly 300 years old. It is a UNESCO Heritage site. Of course you should visit the Solis Opera House, a world class gem. La Rambla is Montevideos version of a city beach, Copacabana style.
That being said, there are some gems of smaller cities in the interior of the country ... Mercedes, Soriano, Salta, Paysandú ... they all live up to their names ... with a much more relaxed atmosphere and far cheaper.
But the crown jewel of the entire country is Colonia del Sacramento, a city that has basically been preserved intact from the 18th century. Everyone falls in love with the place but again in February it will be more Argentine than Uruguayan.
But to come back to Monte, you should also visit the Buceos and Pocitos neighbourhoods of the city....they are the epicenter of the best restaurants in the city.