I stayed at this hotel for 3 nights in October. I picked the Arcotel because it wasn't just within a short walking distance from the train station and the bus station (where I arrived early in the morning) but also relatively close to the city's main attractions. Not one single time I had to use the tram in Zagreb because the hotel was just conveniently close to all the museums and other sights on my "to visit" list.

As for the hotel and it's facilities:

I arrived at 3am in the morning and since I had nowhere to go, I decided to go to the hotel to ask whether it was possible to drop off my bags. I didn't want to take my entire luggage with me while searching for a cafe where to spend a few hours while waiting for the city to wake up.
But that wasn't needed. The friendly woman at the check-in counter already gave me the room keys and let me go upstairs to my room. A pleasant surprise for me because a little bit of sleep was exactly what I was in need of.
The employee who was on duty during check-in wasn't the only friendly staff member though. All of the ones I had to deal with during my stay were always very friendly, helpful and always greeted me with a smile.

My room was clean and quite spacious, maybe even a little big for me as I was staying there by myself (it was a double room with single occupancy).
I liked the design of the furniture, it was very "retro" (if hope that is the correct term for it). The bed was very comfortable and I liked the extra pillows.
There were also 2 apples in my room as a little welcome gift. I found this a very nice gesture.
The prices of the items in the minibar were also reasonable.
Although my room was facing the main street, you could barely hear noises from outside. I just had to open the window from time to time because the autumn sun which was shining directly through the window made the room heat up a bit.
The room didn't just have a big plasma TV but also a DVD player.

The bathroom was clean too and HUGE. It had a bathtub with integrated shower.

Breakfast was included with my room rate. They have a continental breakfast buffet with so many delicious things to choose from. They have different kinds of cereals, scrampled eggs, different types of bread, many different cheeses and sausages and - not to forget - fresh fruit.
After such a rich breakfast I found myself skipping lunch almost every day. That is also the reason why I never visited the hotel's restaurant.

The hotel also has a spa and gym. The whirlpool is clean and very relaxing. The massages which are being offered there also also reasonably priced and a great way to relax after a long day of sightseeing and shopping in the city.

I also visited the hotel's very own bar for a cup of coffee. The staff was also very friendly and the beverages were delicious.

Next to the hotel is a cinema where you can catch movies in English. If you don't have a place to go in the evening, then that's the place to be.

As for the free WIFI at the hotel, it was very fast and the signal was also very good in my room as well as at the hotel bar and in other parts of the hotel.