Hostal Apolo was the final hotel for a small group tour I recently did. All of the hotels were pretty average, but Apolo has the distinction of being the worst by quite a stretch.
Technically it should be okay. The location was close to the tapas bars, the room was clean, the linen was clean, the room was large, the lift worked, the water was hot, so I spent quite a while trying to figure out why I disliked the hotel so much.

I think it has two main issues. One is the location - it's in a street full of Chinese import companies, which is somewhat bizarre when in Spain, and also pretty dark and grimy. But the main issue is maintenance. The lino on our floor wasn't flat. There were marks on the walls no-one had bothered to wash off. The back of the bathroom door looked like a large dog had tried to claw its way out, and the highlight was when I tried to hang the shower hose on the rail and the whole thing fell off the wall. Another highlight was when returning to our rooms in the evenings, we had to show the man behind reception our hotel cards to prove that we were guests.

For some of the travellers on my trip, this hotel was enough to put them off doing another trip with the tour company.

The main advantage for this hotel is that it's in a good location within easy walking distance to everything, and it's reasonably cheap. The rest was incredibly disappointing.

One of the main receptionists really made our arrival hellish, ranting at us angrily in Spanish (we understand a little, but he wouldn't slow down and use simple words) although we realised much later he knew enough English to have communicated his point: we had to pay for our stay in advance. He could not have been ruder on all occasions we dealt with him, and it seems he was like this with all guests. Might help if you're fluent in Spanish.

We booked a double room but got two single beds - very uncomfortable and hard. You get only one small flat pillow.

The rooms all seem to be smoking rooms. The curtains, bed covers and walls reek. The bathrooms are fine but the towels smell of old pasta and I had a big ball of hair in mine. The toilet flush really is quite something - very powerful and loud.

The internet is expensive - we paid around 15 euros for 3 days. Bear in mind that the majority of Madrid has free wifi and most Spanish hotels we stayed at had free wifi too.

After checking out, if you want to leave your bags at the hotel, they're kept in the reception's foyer hall. They assure you there's always someone watching, but we weren't too excited by the free access.

Over all, my advice is to keep looking. There are much better options.

Firstly, be aware that there are two "Apolo"s in this area of Madrid: this hotel and Hostal Apolo XI. Don't print out directions to the wrong one like we did ;)

We arrived here quite late at night, and my first impression was that the area looked quite run down, lots of boarded up shops and graffiti. Unfortunately, this was when my opinion of the hotel was at its peak, and it was only downhill from there.

I will start with the few good points I have to make. The room was spacious but sparse, probably of two-star standard (which is enough for me). The room was also very clean -- housekeeping do a good job. The hotel is about a minute away from the La Latina metro station, providing access to Madrid's efficient underground system. It's also not too far a walk from some other parts of the city.

Now, the downside. The hotel was awkward to get to from the airport, requiring two changes on the metro and taking about an hour. The check-in process was quite depressing; there are prisons that provide better customer service than this. The man at reception may have misread the job description.

Our room was a twin even though we booked a double. We couldn't get the safe to work and the window wouldn't lock properly. Every room in the building also seemed to be equipped with one of the loudest toilets known to man. Can they not fit mufflers to these things?

The toilets were not the biggest noise problem. That came mainly from outside. This hotel must be situated in an area with many pubs and clubs (although to be honest we didn't see many!) as the drunken noise from outside was unbelievable.

Admittedly I am a light sleeper but my partner could sleep through the apocalypse and even he found it impossible to get some rest. Not only did we have problems with outside noise (shouting, sirens, traffic, the council emptying the glass recycling bins at 1am every night) we also had problems with very loud people returning to the hotel very late and proceeding to wake the dead (which is how I felt after so many sleepless nights).

We encountered two further people working at reception, neither of whom spoke English. This would not bother me, if not for the fact that their English-language website clearly states that English is spoken at reception. It also became a problem when we found ourselves locked out of our room halfway through our stay as our key card randomly stopped working. That was definitely extra hassle that we did not need.

When rating this hotel, I have to take everything into account. The hotel may not be able to do much about the noise or the location, but I can't ignore these things when, for me, they pretty much ruined a trip to a lovely city. Cheap does not always mean good value.

I just stayed four nights here and whilst I agree with the comments about the noisy bathroom and general plain decor, if you literally want to rest your head on a comfortable bed in a room that is thoroughly cleaned every day, you won't get better for 45 Euros a night. The staff are very friendly (more so if you speak a bit of Spanish) and the location is perfect for Plaza Mayor and La Latina. You can pay double in other capital cities for something an awful lot worse!