Location is what makes this place stand out: you're right in the heart of Alfama - just 20 metres from a Tram 28 stop - but it's also very quiet because it's a small, pedestrian street.
That said: when we were there there was a lot of building work going on in the building opposite. It was meant to be completed in the summer of 2018 but it's clearly going to overrun well into 2019. So, if you're visiting during the week and intend to spend time in the apartment during the day, be warned that it may be noisy! This shouldn't be a problem, though, if you're out and about visiting the city, or over the weekend.
It's quite a cosy apartment (read: small) especially if, like me, you're well over six-foot tall. But it wasn't too much of a problem. The bed in the main room is still big enough - although it's a bit of a tight squeeze in the bathroom. I wouldn't recommend this for two couples - although there is a second double bed, the top room has a very low ceiling, so you'd bump your head a lot. But it does have a terrace that looks out over to the sea, which is lovely (provided you're not trying to read in the sun while the builders opposite are hard at work!).
Hosts Monica and Carlos were great. We never met them in person, but they provided prompt tips and suggestions, and were quick to warn us when a storm blew into Lisbon. If they were there during our trip, I'm sure they would have made sure that there was replacement toilet roll in the loo etc, but it wasn't too much of a problem buying some of our own.
Small word of warning: the man in the apartment below smokes a lot and so, if the windows are left open, you get the smell of cigarettes wafting in. He also coughs a lot, plus snores very loudly - and the ceiling is v thin, so, well, bring ear plugs! That said, the location - despite being in the thick of the old town - is very quiet, with no street noise at all.
Very steep and narrow staircase - but shouldn't be an issue unless you have mobility problems. All in all, it was a great base from which to see Lisbon: within a flash, you're in the heart of the Alfama, with so many sights and restaurants on your doorstep. One recommendation: do the tasting menu at the Boi-Cavalo restaurant just around the corner - a culinary highlight of our trip.
Thanks for being excellent hosts, Monica and Carlos - and thanks, too, for the complimentary bottle of red wine: a nice touch. Your written tips and suggestions for our trip were really useful and very informative. Obrigado!