Even if you are going TV -> DVD you still are going to get noise in the cables which degrades and image, so i'm not going to go into that. However, even if you forget about that it will still look similar. And I shall prove it!
Here are some screen caps which I took.
First a cap from the SDA movie beside one of MFlatley's WIPs (First Super Metroid thing I found on my smv folder)
Here they are blown up 2x so you can see some actual detail.
Ok, big difference yes. The next image is a screen cap from me encoding that section MFlatley's WIP with a similar bitrate used in the SDA encoding. This is without any of the further optimizations which are used by encoders at this site, but I'm not sure if Radix/Nate use any advanced encoding options anyways.
Wait a minute... that looks fairly similar to the SDA run! I had also actually taken photoshop and added some noise/blur filters to the emulator screencap to simulate an encode and make it look the same as the SDA encode too, but my power went out and I lost that picture, and didn't bother to remake it. Also, what does that really prove anyways? I can use photoshop I guess.
The only thing left is the color of the two are different. Which if you ask anyone who has dealt with PAL/NTSC colors about, they will be able to give you an easy answer for. NTSC color emulation isn't accurate, it may not even be possible (A joke acronym for NTSC is 'Never the Same Color'), so an emulator will NEVER be the same color as on a console. However, if a TAS was played back on a TV to be recorded with a VCR/DVD/Whatever to be submitted to SDA it would get the NTSC color effect and will look different from the emulator.