Our group tour spent one night there while travelling through. The staff really went the extra mile. Met our bus and unloaded all our bags.

There weren't enough double rooms, so several people who were normally sharing a room, got their own room.

The best part of the room was the AWESOME air-conditioner. It got the room so cool, we didn't want to leave the next a.m.

One computer set up in the lobby with free internet. Ok breakfast.

Within walking distance to the bridge and several stores nearby.

This is a standard business hotel in an out of the way town. It is not every going to be cited as a top performer when compared to Paris or New York, but it does the job for Mostar. My room was in good condition if older. It was a corner room, so fairly large and bright with a balcony. The breakfast was subpar in my opinion, but I have seen worse. The location is about 10-15 minutes from the old town that has most of the action these days (such as it is). I highly advise that you walk across the bridge to the Muslim side and walk into town that way as it is a much more enjoyable walk than the Christian side (you are staying on the Christian side although these days people seem to mix freely; nevertheless, families continue living where their parents lived which is where their grandparents lived, and this town generally seperated by religion), which is along a plain busy street. The Muslim side will has a number of cafes and small shops most of the way and is a very pleasant walk. However, both sides of the river are safe.

the followings are excerpts from my travel diary:
I was quite sad to leave the nice Pansion I was at, in the old town and so simple and cute- but sharing a bath with 4 strangers is bad enough, but having partitions instead of walls - including for the bath- was too intimate for me. so I checked myself into the Hotel Ero....
The ERO has the impersonal pseudo-luxury of a 40 year old building mostly used for OSCE personnel. The shower must have been bought 2nd hand from a bankrupt kibbutz- but it is all mine !!
for this privilege I will pay 50 instead of 10 € a night.... "
two days later:
"...the Ero may have been a mistake. for the luxury of a private bath I have a lumpy bed, thin blanket and no hot water. I think I miss the Pansion Oscar. Then again- I have internet access!"
and the next day:
"...Back in Mostar, the hotel had my room changed into a similar one that was less dilapidated and with actual running hot and cold water-ah, civilization!"

We arrived by car in Mostar in wild, windy, cold and rainy weather. The room was cold as the heating had not been on and it took overnight to really get warm - but then it was. Room was a bit bare and basic but quite large and light, with a great Mostar view out the balcony window (see pics). Close-ish to the old town, within reach of restaurants - try the Veranda across the bridge. Hotel restaurant itself is not that great but filled the bill on the first night when we didn't want to venture out into the weather. Staff are civil. There is parking for your car (you have to compete with the US embassy).

We notice some small accommodation places right next to the old town and would probably have a look into those if we ever came back. More convenient and picturesque.