I have my SSD attached via my top dock on my corsair 650d the ssd is the kingston 240gb v200 and I'm transferring to my raid 0 caviar black 2tb x 2 the files are my cinemaDNG files from blackmagic camera and I get about 45MB/s transferring 180gb. On my macbook retina I don't know the speed but I transffered another set of files and it did it in less than half the time.
More abouttransferring raid 50mb
check you have your SSD connected to the fastest SATA port!!
Check with ATTO Benchmark that your SSD is delivering the right speeds in upload and download!
does the topdock connect via USB? if so, there's your praablem!