@DecoManM5 

You've made substantial investment buying five Deco M5s, but your choice was influenced by somewhat misleading marketing materials.

In reality, you can get WiFi speed of just under 500Mbps from Main Deco. You can get half of that, 200-250Mbps on Satellite Deco. If you happened to have remote Satellite Deco connecting not to Main but to another Satellite Deco, that remote Satellite Deco can only deliver speeds up to 100-120Mbps.

It is what M5 capable of, in real life and in ideal conditions, with everything properly placed and tuned. On WiFi5. With mobile device about 6-10 feet from Deco, not further. With ideally placed Satellite Decos in regard to their link to Main Deco. With no or very little WiFi interference from household appliances and neighbors' WiFi networks. 

If you would like to, I can give you few ideas on how to troubleshoot (and possibly improve) Deco mesh performance, as 50-100Mbps download speeds sounds a bit low for Satellite and definitely low for Main Deco. Still, no matter what you do and how much time you'll spend on it, you won't get better speeds than I listed.

If you are not happy with what Deco M5 mesh is capable of in real life, I would suggest packing M5s and sending them back if you can still do that. You will need to research for a better alternative, from TP-Link Deco or other brands. 

  @Alexandre. Thanks, I didnt realise thats how the speed works and it slows down with further satelites connected.

i am looking at the Deco X90 mesh now as it looks like it has lot more power and with less units should be able to send faster signals.