From my Synology DS209 gigabit with standard 1500 byte frames.
Running warmup...
Running a 500MB file write on drive y: once...
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Average (W): 29.01 MB/sec
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Running a 500MB file read on drive y: once...
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Average (R): 54.05 MB/sec
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From my DNS-323, firmware 1.08, gigabit with standard 1500 byte frames.
Running warmup...
Running a 500MB file write on drive y: once...
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Average (W): 10.93 MB/sec
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Running a 500MB file read on drive y: once...
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Average (R): 14.14 MB/sec
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I paid $129 for the DNS-323 and $299 for the DS209.
I'll take the performance of the Synology for the difference in price. After I get done adding drives, the price difference isn't all that great for the added performance. The Synology also seamlessly supports as many USB disks as you like, multiple printers, UPS, etc.