I've used Happy Limo several times. Pros: usually on time, often get upgraded, price isn't the highest nor the lowest, cars generally clean, drivers pleasant. Cons: drivers aren't as helpful as other's I've had with luggage, etc, limos a little on the older side.
This past cruise, I was a little unhappy about two things. First, our pick up was pressuring for a good tip...granted he picked us up in the middle of the night due to delays, and I would have given him extra anyway...I just don't like having it suggested to me so strongly. Second, going back the limo was an upgrade, but it was dirty, the sound system was broken and the TV/movie and air system kept shutting down. We were tired, short drive, no biggie, but still...
We'd use them again, but I'd be tempted to try someone else if the price was right.