I've always been under the impression it's a wee bit naughty in some places.
We spent a month wandering around Cuba in 2008 staying in a variety of places - casa particulares (sort of basic B&B), three nights AI in Guardalavaca, hotels and the best of all in Havana a room above a flamenco bar (twice!). This was before things became a bit more relaxed and independent tourism became easier. We used buses, taxis and a couple of internal flights, one of which was a seriously nervy experience and the crash in May of this year didn't surprise me.
The aircraft we flew in from Havana to Holgein was a 737-100, the original from 1965 and the interior had been painted using white emulsion paint with a touch of blue gloss to brighten it up. More brush marks than you could wave a roller at and numerous broken or missing seats. However the most concerning thing was the sounds coming from the undercarriage as we started to taxi, imminent bearing failure came to mind. It stopped at three rural airfields on the way so had to endure an extra three take offs and landings.
Found the people mostly friendly and welcoming, those that weren't were mainly just shy or cautious about fraternising with foreigners.
All in all we had a great time, the rum, la musica and the flamenco (very different to the Spanish style) coupled with seeing at first hand many places we'd only ever read about - Moncado Barracks where the first attempt at revolution failed, Santiago where Castro gave his big speech when he won, the architecture in Havana & Santiago and of course the cars...
JF