just got my unifi package to 500 mbps.

My house is a double storey terrace house. TM gave the stock Fiberhome mesh router, The main router is at upstairs with beside the modem, and the second router (mesh) is downstairs.

Upstairs rooms can get 300 Mbps - 500 Mbps

Downstairs living room, when connected to fiberhome mesh (downstairs) can only max get 250 Mbps.

Would like to get opinions to improve and so that i can get downstairs living room 500Mbps (other location downstairs not prioirity) , should i get:

1. XE75 deco 2 packs

2. Archer Ax73 (upstairs) and downstairs to use RE705X

Thanks