First, >500 Mbps is a tad slow for a wired gigabit network. I’d have expected to see a figure closer to >900 Mbps, but 500-ish Mbps should be more than sufficient if that speed can be reliably and continuously achieved.
As to your problems with autofs, two points. First, if your server will be running 24/7, you might generally find it easier to go for the fstab solution, though autofs will also work. Second, since you’re having problems with autofs, I’d recommend that you take a step back and see if you can manually mount the share from the command line. Remember to create the mount point first. If you’re unfamiliar with the syntax, here’s an example: Network drives - #5 by darwindesign