If you are planing to attend an expo or event at Miami Beach Convention Center you are lucky. The center is 2-5 min walking for Lincoln Rd, where you have shops, restaurants and etc. You are also walking distance form many hotels. Itself Miami Beach Convention Center managed really well, and they try to get best venues to Miami Beach.
For the last 11 years, I have gone year every March for our Industry Trade Show. Even though this building was constructed in 1957, it is still a great location for conventions.. It is going to be broken down soon and a new building will come up in it's place. Lets hope it is even better.
I live in Miami (inland) so I'd say this center is not so practical when coming from outside, especially for events like Art basel. I have given up going to AB because you can't find any place to park then. There is a cheap municipal parking lot 5 minutes walk from the center but you can't use it for major...