So I got a chance to do a little more copying today. Tiny files are still slow to copy - 20MB/s - no surprise. What did surprise me was when I copied a large file - 100GB - I got 9GB/sec!!! I'll probably average around 600GB/s as I have 2 file types I copy most often - BR - 25GB and TV shows 700MB to 1.5GB.
Uh...I assume your numbers are actualy Mbps and Gbps and not MB/s and GB/s. The 20MB/s for tiny files sounds fine, but I don't see how you could get 9 GIGABYTES per second with a 10 GIGABIT per second connection.
MB and GB ALWAYS mean BYTEs. Big B, bytes, little b, bits.
Typical convention is also to write it as MB/s or GB/s and Mbps and Gbps for Megabytes/Gigabytes per second and Megabits/Gigabits per second. You could also write it Mb/s and Gb/s or MBps and GBps, but it does lend towards a bit more confusion writing it that way.
Granted I don't know you exact process, but I generally only need to do HUGE transfers if I am replacing a disk array (which, thankful is exceedingly rare as I am only starting to get in to a total disk replacement in my server an desktop for the first time in about 3 years). Around 1.7TB of data, so it does take awhile, even at 2Gbps. But, meh, very rare.
More commonly I am backing up from my desktop to my server (occasionally server to desktop if it was data pushed from my tablet or laptop to the server). That said, even with a weekly job running, I am generally only talking 3-10GB of data as my photography and occasional BR rip (of a new movie I've bought) just doesn't generate that much (and the heck with keeping the BR ISOs, I transcode everything as that is the only way I can take stuff with me, and that is half my watching is on my tablet on the go...and I am not sitting and waiting for stuff to transcode, that and my storage costs would go up easily 3-4x instead of keeping just the final 720/1080p mp4).
A regular 1Gbps connection would be just fine for those, but of course occasionally I do transfer stuff during butt in the seat, hands on the keyboard time, and if I am transfering a 6GB file or something, I'd really rather prefer it take 26 seconds instead of 52 seconds.