Lived down here in Miami my whole life. To go through your list:
Abundance of sexy women - Yes, overflowing with girls, predominately Latin, the rest being maybe 15-20% or so White. Almost no Asians and a very small number of Black women. Miami has variety of Latin women, but not variety like LA or NYC. Many are massively entitled, but many are incredibly good looking.
Quality of life - depends what's important to you. I personally find the constant heat completely intolerable, but I don't know the first thing about shoveling snow out of my driveway either. Traffic is horrendous, but if you live near your job or work odd hours or are self-employed and work from home, you might not even notice this. The novelty of the beach wore off for me many moons ago, but if that's what you're looking for, there's a ton of great waterfront spots from South Beach all the way up to Fort Lauderdale (about 30 miles North of Miami)
Cost - high. Life is not cheap down here. A 1/1 spot in the downtown/Brickell area (maybe the most booming part of the city right now) can easily run you at least $1,500. There's more reasonable housing inland, but most of the suburbs are pretty boring. Every bar and club will ask for a vital organ in exchange for a beer/drink.
I think it's a pretty vapid city, but I have a few friends down here who claim they love it (moved from up North too), also known people who tried it out for a few years and left claiming that they hate it.