This was our first visit to Portugal, and we really enjoyed it. The villa was great, really spacious and well equipped, everything in good repair and clean and tidy when we arrived. There were only four of us, but the villa would comfortably accommodate six. The outside space is a great feature of this villa - all the different terraces around the villa and on the roof, the sheltered sunny courtyard, the swings, the citrus trees, and of course the pool. We didn't quite have the weather to be able to enjoy the rooftop terraces as much as we would have liked, but then this was April. We paid for the pool to be heated, which wasn't cheap but was well worth it because we were able to go in the pool every day - even the two days it rained!
Any downsides to the villa? Not really. The only thing I would mention is, I had trouble with the locks on two of the sliding doors - I couldn't get them to lock properly, a good firm yank would open them. This isn't really a problem because there are stout metal shutters outside every door and window, it just means that you have to go round closing all the shutters before you go out / go to bed (you will almost certainly have been round and opened them all earlier, because the villa is quite dark with the shutters closed).
We had a car and drove ourselves from the airport - the villa was easily found with help of Google Maps. The car was handy - it was useful for shopping trips to the Intermarche about a mile away, and we were able to visit Alvor and Villamoura, as well a theme park and Lagos Zoo - but I wouldn't say a car is actually necessary because we loved Carvoeiro itself. The town is in easy walking distance - we walked in three or four times, takes 15-20 minutes - and has everything you could need in terms of shops, bars and restaurants. We ate in a different restaurant every night, had a good experience in every one of them, and there are probably 20 or 30 more that we didn't get to try. The feel of Carvoeiro was just right for us (family with children aged 10 and 12) - we liked Alvor and Villamoura for different reasons, but I think we will definitely base ourselves in Carvoeiro when we return to Portugal.