I haven't touched NetDrive in a while so I got motivated and just spent two hours adding a 1 sector read ahead cache into the code. After a read request the server sends one extra block, and the DOS side caches it. On the next read the DOS side checks the cache.
Running CHKDSK against a 200MB drive across the network to a server that is 47 milliseconds away was taking around 26.8 seconds. Now it takes 17.69 seconds.
Yep, this feature is worth doing ...