After installing the Wintun adapters on my Win10 desktop PC a while back my dl speed rose from around 30-45Mbps to around 110-120Mbps on my then 200Mbps Virgin Media broadband. A month ago I upgraded to the VM 500Mbps package and at first I could only get 180-200Mbps D/L speed. I immediately blamed Virgin but when I solved it it was nothing to do with Virgin but my Linksys router. I run the VM SH3.0 in modem mode into my Linksys EA7500 router.
I have one cat7 ethernet cable running from the router to my PC and another running to the Samsung tv in my living room. Other than that I have my wifes laptop, mobile and the Virgin Tivo box running on the Linksys Wi-Fi. In the Linksys settings there is a box in the prioritization options which you need to set with your broadband subscription speed x 1024. In my case when I had the VM 200Mbps package it was set at 204,800. When I remembered this I went into the Linksys settings and changed to 512,000 and hey presto I was getting 380 - 400Mbps straight away.
I have also found that the server you choose to connect to at AirVPN and the time of day also has a bearing on your connection speed, which is why I have a preferred list of Air servers which have given me excellent d/l speeds in the past and do an online speedtest each time I connect to ensure I get a good connection. Something else is that I only use AirVPN a couple of hours in the early mornings and an occasional Sat/Sun afternoon, perhaps if you are using AirVPN 24/7 these results will not match I don't know but I am quite happy getting 50-75% of my broadband connection via AirVPN and 100% the rest of the time all things considered.