Unless you do heavy and large downloads the 150 MB/sec should do fine as long as all works with the current setup concerning your cameras. The cameras are probably the deciding factor as they are the most numerous. If your current 20-25 MB/sec has worked with the cameras the lower 150 MB/sec should do just as well if not better.
My download connection averages ~116 Mb/sec and I oaten stream videos through Prime Video, Paramount, Disney, Netflix and HBO Max. Unless the bandwidth is shared with other systems this streaming really only requires ~30 Mb/sec max. for 4K.
If you went with a higher speed over the 150 Mb/sec you MIGHT see a slight difference in web page loads and such but it would be minor. As to what we humans see download speed of over 30-40 Mb/sec is usually minor. Sure there IS a difference but how important is it if a site page loads in .25 seconds or .5 seconds?
Now there IS a difference between download speed and throughput. Many ISP systems give high download speeds but throttle the throughput. Boils down to how much data they allow to go through within a certain time regardless of the actual download speed.
Ahhh, A second thought on your cameras. Do they do transfers via your internet connection? If through internet you would probably see some improvement in performance but it done strictly through your router you will probably see no change as that would be a local network connection which would not involve your internet connection.