You can manually select a server not under PLDT. We have some apps hosted sa US West so I often ping ISPs near Cali where the submarine cables terminate.
For me the acid test if I can download from Steam (or Origin, Ubisoft, Epic etc), Microsoft, or the high seas and get the rated speed. Usually kasi once you get to the 300+Mbps range you're limited by the websites you're downloading from already.
This is pretty solid proof that the connection was going at around 750Mbps since Steam was able to peak at 80MB/s.
For the most part I'm happy with even 200Mbps. Even large downloads finish within the day, any more than that and it's the hard disk space that becomes an issue.