Wireless Performance to ReadyNAS - at my wits' end...

How many layers are you going through to use wireless, you mentioned a Router Netgear WNDR4500v2 and Access Point Netgear WNAP320?
Is the NAS directly connected to the router or one of your switches?
I suspect considerable drop (half speed) if jumping through an access point used as range extender, and possibly further drops if rate changing across units 1Gbps <=> 100Mbps.

For the record, here are my results using the NAS test program:

NAS performance tester 1.4 http://www.808.dk/?nastester
Running warmup...
Running a 400MB file write on drive [Duo v1] 5 times...
Iteration 1:     15.28 MB/sec
Iteration 2:     16.17 MB/sec
Iteration 3:     16.39 MB/sec
Iteration 4:     16.51 MB/sec
Iteration 5:     14.57 MB/sec
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Average (W):     15.78 MB/sec
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Running a 400MB file read on drive [Duo v1] 5 times...
Iteration 1:     20.32 MB/sec
Iteration 2:     19.44 MB/sec
Iteration 3:     17.80 MB/sec
Iteration 4:     19.66 MB/sec
Iteration 5:     22.03 MB/sec
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Average (R):     19.85 MB/sec
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Running warmup...
Running a 400MB file write on drive [NV+ v2] 5 times...
Iteration 1:     26.46 MB/sec
Iteration 2:     25.06 MB/sec
Iteration 3:     24.97 MB/sec
Iteration 4:     24.54 MB/sec
Iteration 5:     25.64 MB/sec
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Average (W):     25.33 MB/sec
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Running a 400MB file read on drive [NV+ v2] 5 times...
Iteration 1:     18.02 MB/sec
Iteration 2:     21.31 MB/sec
Iteration 3:     23.65 MB/sec
Iteration 4:     23.29 MB/sec
Iteration 5:     23.68 MB/sec
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Average (R):     21.99 MB/sec
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