Hi @Sulmtaler1 ,
On a previous service provider's network with poorer reviews on its infrastructure, I've seen as wide a variability as under 1 Mbps down up to around 35 Mbps down as judged from fast.com and speedtest.net with the value depending on the time of day (worst values at busy congested times and best values late at night and also early on weekends).
Is your external antenna directional or omni-directional? I would highly recommend to monitor your equivalent of the RS-SINR signal parameter and, for my MR1100, a value above 10 dBm is good.
From a slight adjustment of router positioning, I was able to improve from sub 7 dBm to consistently between 13 dBm and 24 dBm because the obvious central and raised position was suboptimal and in fact a lower, apparently more crowded position, actually showed better signal strength and I was able to cancel my plan to purchase an external antenna.
I would recommend powerline adapters (Devolo is good, other brands are available), one with a WiFi endpoint, over mesh WiFi. If your WiFi signal is already known to travel badly in your property, I think it's misguided to use a solution which relies further on WiFi signals travelling well. Mesh WiFi makes more sense when purely used to overcome the problem of coverage of a wide area, not suspected poor penetration through walls, floors, and other obstacles.
