Argh!
All this Cuba bashing!
I have been to Cuba no less than 15 times in the past 4 years. The DR about the same, and I am moving to the DR in a couple weeks.
I can tell you...underneath the comments made here, about rules, not speaking with locals...etc., that perhaps these people listened a bit to a cab driver or family.
Every trip I've had...every one...the same things said before, after, etc.
The reality is that life on the street is very much different than the writing on news pages. Communism these days is really just propaganda for the masses. Cuba is a capitalistic place, at least as far as your trip will be concerned.
The streets of Habana will be vibrant, much more vibrant than anywhere in Rep. Dom. You never know what day it is in Cuba. Everyone is walking everywhere, with no destination in mind.
You DO stay with families, then and now.
In fact, I can recommend you to 2 places...both top floor penthouses in Habana with 40 mile views of the sea, looking right at the famous morro Castillo. One is $35, the other $30. Try that in cosmopolitan Santo Domingo.
The families in Cuba are wonderful...they will invite you in for dinner everywhere, just to speak and laugh, when they see you walking by. Remember you are not at risk of crime there like the DR. You will see smiles, not knives and currency swindles.
After dark in the DR, you are at risk of MANY crimes, both property and violent.
The example the earlier post...the friend in Cuba pulled over by the police is normal...but those have been the rules for 20 years. Non-State taxis are not allowed, have never been...but the fun of it all, cruising around with a bottle of havana club that every driver has. They know the risk...it is simply a fine. If your driver is pulled over, which is rare (they know where to drop you off), go ahead and pay the $5-$9 fee for him or her. It won't kill you. You'll be off crusing again in minutes (well, Caribbean minutes, that is).
The locals are so fun...and they love Americans, Europeans, Canadians, even though the govts. are warring in the press...you will be loved, and not just for your money.
The partying in Cuba is much more carefree than in the DR. The streets are 4 times safer, and the spirit of life is like the DR squared. And the DR has a lot of life!
There are no rush hours, no hiding cell phones, etc.
As my friends and I say, when we want a nice Americanized stay, we go to the DR. Cuba is a gem, like traveling back in time. And your visits really do help the people, who by the way are probably happier than you or I. They are just deprived of some things we have, most notably Mercedes & McDonalds. But their spirit and life, beyond the small talk of rules...you will make friends in 8 minutes everywhere.
Don't get me wrong, I love the DR. A great place. Much more comfortable particularly if you are used to the 1st world, want a reservation, working hot water, and are not very good at speaking Spanish.
But you certainly will not pick up a dozen persons standing by the road during the course of the day to give them rides along the autopistas...(who will laugh and babble on about their lives, families, and yes...take a drink of Habana Club rum...or give some to you :classic

, share lunch and dinner with 2 separate families in 1 day (in their living rooms) you just met strolling by, and walk the streets of the largest capital city at 3am...alone...marveling at the majestic buildings and architecture, without watching every passing car looking for a machete.
The wedding will be amazing. Cuba never disappoints.
Have FUN!