Yes, I’m using WiFi, and paying a friend for use of their Modum which sits nearby ‘pumping stuff out’.
So, you pay your buddy to use their wi-fi? If you stop paying do they change their password?
Geography matters - WiFi is radio waves... Metal messes with them, so if the router is on the other side of the kitchen, or a furnace room, the appliances can effect or even block signal. I have seen large duct-work do the same.
As far as the technology goes, if the router is older, or your computer is older (say, WinVista to early Win7) upgrading may be useful - an 'N' series router AND network card (has to be both) will vastly improve signal and speed. If it is 'G' series, consider upgrading.
Also a wireless to wireless, or preferably wired to wireless repeater or hotspot can be employed (another router of your own hooked to his would do the same thing PLUS privacy)
And finally, if desktop, Wired is much faster and more reliable than wireless.
it sounds like a wifi issue. Lots of things can interfere with it. Where you place your devices that broadcast your wifi radio signal. Wifi is broadcast like AM radio where anything that blocks your line of site to the wifi radio causes issue.
Things that can help. Make sure your wifi router or access point is placed as high up as possible away from metal objects. Ceiling mounts, tops of book shelfs, even stacking stuff and placing it on top can help. If you are getting a full wifi signal or at least a good one and you are still slowing down, that indicates channel overlap. Wifi channels 1-4 and 5-11 overlap each other. You need a tech or to do some research to troubleshoot this. If the guy running the router is willing and able, have him change the channel to either 1 or 11 as a test.
These kinds of issues are really tough to troubleshoot remotely. You may be able to see your connection speed on your wifi enabled device by looking at the wifi connection properties. I can on android but not on windows mobile or ios without extra apps. I don’t know any since I use Inssider on a windows pro tablet. Adding an wifi extender can help but you need to check for channel overlap and bad radio placement first
I hope some of this helps. It gets complicated fast . Think of wifi like radio waves. Your actual Internet at the modem is like cars moving down a freeway. Every packet of info is a car driving along and the quality of the road can affct speed.