We had a great experience at Cool Loft. Location is perfect (a few steps from tram 28 and metro), apartment is spacious and cozy, with everything you need, and the staff is very kind and helpful.
To climb the 5 floors after a full day walking through Lisboa can be tiring, specially if you have to carry your 2 year old child, but that's OK... It's worth it.
Just one suggestion: curtains for all windows at the main bedroom. It gets very bright when the sun shows up. Other than that, no complaints.
I would stay there again. ;)