Rui and his wife were very friendly and helpful so I'd definitely recommend staying at one of their apartments (But see below if you have kids). The place is well located, 5 mins walk from two metro lines (red, green at Alameda, (note that Arroios station is currently closed), on a quiet street (although we had loud conversations at the bar below at 2am on a couple occasions which woke us up). The area is not as touristy which means more authentic (and cheaper) restaurants, yet you'll be in Baixa in 20-30 mins by metro.
What didn't work for us was the lack of sleep. I had overlooked the fact it was a loft (duh), i.e. no possibility to close rooms and don't recommend it if you have very young children, who need a darker environment (impossible there). Or if you need a really dark environment yourself.