We had a good time at Helena's apartment. It was nice and clean but an airconditioning would have been great because it was a really warm apartment. The portable airco did not do the job because the equipment was not complete.
The apartment is in the middle of Bairo alto, a bustling neighborhood at night. The noise did not bother us, but maybe in the weekends you can experience more noise.
Nonetheless I would recommend Helena's apartment to friends and family.