Well I`ve got Tropico 4 and just now got Tropico 5 cos of the sale.
The games are similar, but 5 misses out some things I liked in 4. For instance, there doesn`t seem to be any election speech or choices like in 4.
I also found 5 a bit boring and stopped playing even before getting to the present day compare that to 4 which I was on through several campaigns. Also the music is different apart from one track and I really liked all the music in 4.
You do get more avatars as part of your `family`, but not really much choice on how they look, for instance I wanted a male avatar so I held a muscle competition and got a woman?? It all seems wierdly random.
Maybe I need to play 5 more, but so far I`m glad I didn`t pay full price for it when it was first released.