We did stay in Avenida Park for 4 nights. Hotel did not disappoint. Friendly staff at the reception. Our room did had a good size for 2 persons for 4 nights. We never experienced a problem with warm shower water. Room was cleaned every day, and also new towels every day.
Breakfast was simple, but more then sufficient, indeed the breakfast area is a little limited, although we never had a problem to find a table at 08.15 in the morning.
Located very close to metro stations Parque and Marque Pombal, both on a few minutes walking distance. It can be a bit noisy if other guest dont take this into consideration, but it didn't bother us.
So we would not hesitate to return to Avenida Parque if we would go back to Lissabon