As a family with two youngsters - a toddler and 3 month baby - it was great to have the comforts of being in a lovely home with kitchen and washing machine etc.
Slight negatives - location right by the road makes it a little tricky to walk with toddler and baby in buggy but this was only 2-5 mins of inconvenience a couples times a day max.
Secondly the location required reversing uphill from a narrow road into a narrow driveway to park the car (especially in a manual car). But by about the 3rd or 4th time, this became less of an issue.
The biggest watch-out is that the location of the apartment does not appear on the SatNav - it took us to an entirely different part of town - supposedly same street name in the same town (Oeiras).
Back to the positives - it was great being so close to the stretch of beaches and we grew to really love the Oeiras area by the end of our stay. Also the drive into Lisbon, taking the non motorway route, with a water view and a sunny day was quick (20 mins) and pleasant.