For sure DECA should be no worse than wired Ethernet and typically it will be better.
Performance (between two good modules ) seems the same as before I had the DECA installation, and it was fine then.
Just to "play," I went to Speedtest.net and ran a test with my laptop connected to a DECA module. I got around 12Mb down, where it would normally be around 20Mb through ethernet. Of course, DECA is optimized for MRV traffic, not internet.