need advice on VW stereo systems or aftermarket

[Aweful_Truth]

right, currently i have an alpine double din unit in the car which is very very good, has the built in 4x50w amp, it connects to my iPhone, plays cds, dvds and also has a jack for when some one doesn't have an iPhone and wants to play some of their stuff so basically its a great unit. but I'm looking to go for a more oem look. so far I've spent a good £800 upgrading the speakers with Massive slims in the front, Hertz in the back massive tweeters (which are amazing) and a mid size alpine subwoofer for kick but not too chavvy.
so
i was wondering if a VW RNS unit will be able to give as good a quality as the alpine does or if i should stay aftermarket and go for a newer alpine or pioneer? the satnav isn't an issue as i have a high end tom-tom all i need the stereo for is its job of providing top quality sound but needs to be able to connect to my iPhone
all thoughts and suggestions welcome 

[sub39h]

dunno about sound quality but what about this:

http://www.kenwood-electronics.co.uk/car/vw

has sat nav too tho

[jameelno1]

Go pioneer or alpine they will give u the best sound and the function to connect your iPhone
My brother has the pioneer avh-3300bt does evry thing he needs cost between £250-£300 or get the newer avh-8400bt that a little on the expensive side thou
The rns510 wont give you that flexibility on the control of your sound as the aftermarket ones plus its rms out is only 20rms as the pioneer and alpines are 40rms