Mountain Ash - Thomas St is one large hill, so gorgeous views if the house is towards the top. You're not far from Perthcelyn, which has a reputation of being a shithole. Roads around there are typical valley roads with too many parked cars. The train station is too far to walk if time is important, but trains are half hourly (after lockdown is over).
The Mount hasn't got a great deal going for it. Some typical valley pubs, few shops, all looking run down and has seen better days. Nowhere decent to eat, bar perhaps the bowls hall. Lots of outdoor space, walks. Aberdare close by. Comp is nothing to write home about. A few good choirs there. Road access out of the valley at either end could be better, the A4059 at peak times is very slow moving.