You can run the RCD330+ most definitely!
I just got mine in and it took about one beer plus a half to get the stock Premium setup out and the RCD 330 + put in.
Now we have Apple Carplay/Android Auto and it works flawlessly.
Two things we lost (actually 3) was the CD changer, XM radio, and AM radio (bummer).
We have always wanted to stream things but didnt want a different head unit like a pioneer.
The RCD330 is from other markets across the globe so the AM stepping is not similar to the US. However, you can always stream your station if you have an app for it.
Being able to have a color touch screen, PHONE works great, etc.....it was a no brainer for us.
To keep the functionality in the Mk V (ours is a 2005.5) we needed a canbus simulator that is essentially an extension cord for the stock input and is a must have to keep the buttons working and the "potential" battery drain I learned about.
Aux input is on the front of the RCD headunit as well as inputs for USB and SD card.