Paros is lovely and the village of Naoussa is a favourite of ours. We will go back but certainly not to the Zefi Hotel and Apartments.
The actual hotel, from what I could see, looked fine, however we stayed in the apartment block which is obviously older and a little tired: broken chairs, dripping taps, broken cooker rings, worn out mattress. Not major issues but a sign that the place could do with a little refurbishment, especially when the nightly charge is up to 120 Euros.
As others have stated, we also had fresh linen every other day which was good but the actual cleaning of the apartment was not so good (I hasten to add that I am making comparisons with other Greek accommodation where we have stayed).
All of these points were individually minor but collectively niggling. What made matters so much worse was the obnoxious attitude of Mrs Zefi. She was the most sour faced greek I have ever met! Any request no matter how simple (such as swapping a couple of chairs, of which there were many spares around the hotel) was greeted with anger, constant moaning and lots of huffing and puffing.
I know some people on holiday can be very picky and quite unreasonable with what they ask for but I would like to emphasise that we made do with everything except for asking for replacement chairs (the old ones were unuseable). However, from then on Mrs Zefi managed to be even more unpleasant. I even made a point of speaking to the hotel receptionist who spoke English (Mrs Zefi does not), to apologise if I had somehow offended Mrs Zefi. The receptionist told me not to worry as I had done nothing wrong, but that Mrs Zefi is always like this!
If that wasn't bad enough, half way through our holiday we found out about the collapse of XL Airlines. We had booked our holiday through Kosmar who were owned by XL. Unsuprisingly Mrs Zefi was not at all sympathetic and we ended up having to pay for our accommodation again ( but that is another story!).
Like other reviewers we experienced lots of dogs barking but we have had to endure this elsewhere in Greece so I do not blame the Zefi for the dogs. Likewise, the problems we had to deal with caused by the travel company going bust were not the fault of The Zefi so my negative markings have nothing to do with these facts. What I did not expect though, was to have to deal with such an unpleasant, uncooperative and inhospitable hotel owner. There is lots more I could add but hopefully the above is sufficient.
Please be warned!

Allegedly, the management of the Zefi apartments also have a stake in the Insomnia bar in Naoussa town. How appropriate! If you don't suffer from insomnia before you stay at the Zefi, you will after two weeks. I agree with most of the good reviews that it is clean, tidy to a high standard, BUT whether it's the time of year when all the mainland Greeks descend, I don't know. The barking dogs were there, 3 in all in separate places; a yipper, and whiner and a deep throated barker! However they wouldn't have barked or disturbed our sleep if they weren't woken by Greek youths returning from the bars between 3am and dawn. Of the 8 or so English couple that stayed there, 6 made regular complaints about the noise to the rep and the management. Nothing was done about it, yet we, the ones who tried to sleep at nighttime were told not to use the pool between 2pm and 5pm because of the Greeks having a siesta!!! I thought siesta was a Spanish thing! Hey? Why should we be denied enjoying something we paid for while the noisy revellers can sleep until 4pm then go out on the town again? In any case in 14 years of travelling to Greece I have never heard of siesta time! Kalymnos, Samos, Lefkas, Thassos etc don't have it!
We also found the bar very understocked; the German receptionist was very unhelpful, as was the young girl behind the bar and the attitude of the elder lady was quite frightening at times. She would sit in and listen to rep's meetings to hear the complaints and glower at you.
The rooms are extremely clean and were cleaned with fresh linen and towels every second day. But the two girls who were our cleaners walked out on the Zefi just before we left quoting bad working conditions and other things that I can't include. They had had enough! It's a shame that the Zefi doesn't get its act together because Paros is gorgeous; Naoussa is pretty and amazing and the Zefi could contribute to a great holiday if it controlled it's Greek guests. A simple notice requesting silence between 12 and 6am or expulsion would do wonders. As a result we slept 3/4 hours a night.
Some reviews have mentioned "occasional road noise". Make that incessant road noise. While being disturbed lying in bed on morning I couldn't get past the count of 15 between engine noises, whether it be the high pitched screech of a bike or a speeding car. Again something to beware of. I'll definetly return to Paros but I'm afraid it won't be to the Zefi.

Had a very pleasant week in the Zefi apartments last week and was happy with the faciities on offer. Apartments clean and sheets changed virtually every day - a first for me in Greece.

Eating out has rocketed in cost since my last Greek trip a year ago. Prices in Greece have been steadily rising in Greece ever since their adoption of the Euro some years back but the rate of acceleration over the past year has increased dramatically.

Other reviewers have mentioned the dogs around the apartments who bark in the night in the evening and early morinings, apparently with the approval of their owners. There was one particularly noisy mut who appeared to be living in a shack with a corrugated steel roof who was the worst offender. One night we thought that the Greek equivalent of the Environmental Health Authority might have leaned on the owners as we had a quiet night. Alas, this did not appear to have been the case as normal canine service was resumed the next night. I an only assume that the dog owners are deaf or hate foreign tourists and are doing their bit to put us off.

No great problems with street noise for us but we were not facing the road and it was early in the season.

Apart from that the resort of Naoussa is very pleasant. I recommend taking a taxi to the village of Lefkes in the centre of the island and walking along the Byzantine road (Donkey track) to the village of Promodoros ( I think) and cacth the bus back th Naoussa

Brilliant, beautiful Nauossa is the best place for two 23 year old girls up for an adventure. We booked with kosmar and got a good deal. Zefi is clean and basic, with a really nice pool area.
Was noisy, but we were out drinking until late and not facing the main road, so not as bad.
Perfect for a beautiful greek experience on a budget. Don't go if you want to meet lots of English people, but brilliant if you want to live like a greek.