Stayed with my family of 5. Was an okay fit but wouldn’t recommend for parties of 6, especially if more than 2 adults. Apartment has Netflix which is a nice bonus for the kids.
View from the apartment is nice. If you walk 20 seconds down the street you get a spectacular view of the lake and the mountains.

Getting to the apartment from the train station is an uphill walk that takes about 15-20minutes. Not easy to do if you have young kids and/or luggage.
Taxi fares averaged 12-20 CHF to and from the apartment around Montreux. Also, there is a very narrow sidewalk directly in front of the apartment building. Too narrow to fit a stroller or large luggage. Taxi pick up is a bit tricky because the taxi stops in the middle of the street for pick up / drop off.
Walk from the apartment to the lake is quite pleasant and easy even with young kids. We visited Montreux to experience the Xmas market. Overall value is okay but not sure I would return.