Hello,
I have 300MB/Min average on a 100Mb link

That sounds like a decent enough number.  Rates vary.  Remember, the throughput reported by the Ghostcast Server may be different than what the Ghost client reports, if you're using compressed images (one reports uncompressed rates, the other compressed rates.) 

I've always found it's worth the time and hassle of working my way through several drivers, DOS versions, etc to determine the "best" mix for a system I will be working with.  My turn-over rate is about 3-4 years, so it's definitely in my best interest to take the time/effort to go through all these gyrations.  It may not be for you, especially if this is a one-off situation. 

Generally, I create many NIC templates in Ghost Boot Wizard.  for the 755's for example, the 82566DM-2 NIC driver has changed a few times.  I always use the one from Intel, rather than from Dell or built-in the Symantec disk.  But  when I first started, I tried two different versions from Dell, one from Symantec and three from Intel along with MSDOS vs PCDOS.  Yah, it's a pain, but it's worth it for us.  No surprise, for us, the MS-DOS + Intel version worked best.  I've not yet checked the latest Intel version.  I rarely see much (if any) difference that I can reliably reproduce and as we all have seen the vagaries of network bandwidth and throughput vary drastically from day to day.  But if you're in a closed, controlled, isolated network environment (I wish I was!) you may be able to reproduce a solid set of stats for yourself.

Good luck,
PH

Thanks for the responses.