need help deciding about multimedia system

First of all, you'll have to excuse my english :p

ok, so I have bought a new 2011 Skoda Octavia and im waiting for it to arrive (i know it's a golfmkv forum, but it shouldnt matter for this question and this is the best forum i could find) and im considering investing in a multimedia system for it (I guess its called headunit around here).

so Skoda dealership offered a zenec system for 2200$ which is the baseline for me I guess since this system includes all the possible features (reverse camera, localized gps, parrot BT, perfect canbus and MAXIDOT screen integration for the gps instructions). btw, i guess i can order that item online for around 1000 euro then pay taxes, 16%, and pay somebody around 150$ to set it up and be done with a 1700$ "damage" which is still quite a lot for me.

obviously, that's a lot of money :p, so I was considering a chinese knock-off and got kind of confused with the options, and that's where you guys come in!

I need help deciding which chinese brand to get and help figuring out how many features im going to miss from the zenec baseline.

I saw there are some people around here who are professional dealers and installers ("hackers" and tinkers too, I would appreciate any feedback from experienced people), and assuming they have no horse in this race I could use their insight.

so far i saw these models:

audiosources 7608

waywell WD6050

maisun MT-6502

flyaudio

I guess I could get all of them for around 600$ including shipping taxes and setup.

what are the differences, which one is the best (and why, if possible), should I look at a different model/company or should I settle up on the zenec for retail (over)price?

P.S

if your answer consist of a technical term or anything more than basic info, i would really thank you if you could explain it in plain english for us laymen :p