The Beam.  The playbase may have a better sound, but the tech in it is older and is unlikely to get feature improvements that the Beam will get.  Besides, for a smaller TV and apartment, Beam should be plenty.

For better sound, go with the Playbase. It performs better with bass too.

Something else to consider is the space available and how each speaker will look with your mum’s setup. The Playbase is designed so the TV is placed on top of the speaker whereas the Beam will sit in front of the TV. Since her TV is smaller, if you go with the Beam, make sure there is enough clearance so the Beam doesn’t block the bottom of her TV screen.

@GuitarSuperstar - yes my thinking is that although the Beam gen 1 is more modern, her TV is ideal to sit on top of the Playbase. I am also not sure the Beam (even though it is small) is low enough not to block the bottom of the TV like you say. 

Found this deal online - https://www.ortonsaudiovisual.com/sonos-playbase-white.html

Seems like a good deal with warranty and returns policy in place

Also don’t forget the Sonos refurbished option. See this link:

https://www.sonos.com/en-gb/shop/certified-refurbished

So got my mum a black Playbase which was new, in box with seals still intact, bought from a retailer who specialises in refurbished and discontinued audio/tech stock.  Couldn’t be happier plus got it for £399 which I thought was an excellent price.

Just took it round and we set it up and it looks great with her 40 inch Bush TV sat on top. She is chuffed to bits with getting Dolby surround on the streaming apps and DTS on most of her bluray disks.

Without surround speakers or Sub she’s actually hearing 3.0 rather than 5.0 or 5.1, but I still think the Playbase sound is far better standalone like this than the Beam. Of course, adding the Sub etc does make it better…