Any dumb WiFi repeater is going to at best half the maximum WiFi throughput available on your network, simply because of the way they work. In most cases it'll actually about 45% of the speed of the extender as these tend to be less capable than the router.
So you'll normally be better off with a mesh extender. If you've an SH2 then best to use the extender dishes designed to be used with it as no other mesh extender is going to connect directly to the router without using a second device.
*If you have the SH2, seriously consider using those extenders designed with it - not all BT extenders are equal or compatible with meshing directly from the SH2. I don't have a horse in this race as I use an Asus GT-AX6000 router along with Asus RT-AX56 & RT-AX58 AiMesh units.
I only learn by making mistakes and owning up to them - boy do I learn a lot!
