@Gujjar firstly Sky do not offer a choice of hub if you buy basic superfast service over copper from Sky the standard router is tge er115 which is the old flat Q hub. The SR203 is only supplied foc if you need one which usually means your service does not come with a standard voice line so the phone has to be plugged into the router which is the position with all full fibre services and some copper services. Otherwise you have to buy the Broadband Boost bundle at £5 per month to get the SR203. SR203 offers wifi5 and wpa2 security
The SR213 only comes as part if the Wifi Max bundle at £7.50 a month but if you reject the bundle during the cooling off period you keep the hub. The SR213 is a wifi6 unit and supports wpa3 wifi security so can potentially offer faster wifi but of course wont give faster external speeds which are fixed by the connection you buy. As a newer unit it probably has higher processing power.
In my experience both hubs will easily support 13 wifi devices but 7 users at once will hit issues simply from coontention unless you have either Ultrafast+ or Gigafast connection as if you try to split say a 70Mb/s connection 7 ways and you are going to hit issues. If multiple users want to game or watch different video streams you are likely to hit issues as well as neither hub supports QOS which prioritises gaming or video data. You would need to buy a decent third party router to get that support..
=========================================================
65inch Sky Glass, 3 Sky Streaming Pucks, Sky Ultrafast + and Sky SR213(white Wifi Max hub) main Wifi from 3 TP-Link Deco M4 units in access point mode
