Well what exactly are you looking for then?
You can select tracks from the iPod, or have skip/previous and 5 playlist choices.
There are very few aftermarket radios which look good in the Mk5. The only ones that do are the Pioneer AVH range, IMO. Which do have iPod. I had the AVH2500BT in my Golf and it was very good indeed. However I got the Headunit very cheap for £100 (usually £150+).
Adaptor for wiring loom cost £8 but then my mate did all the pin-outs so it was plug and play (was hard wired previously)
Steering wheel control adaptor was £50, faceplate surround was £15, so you're looking at around £200 in parts alone, double what an xCarlink is.
The non bluetooth xCarlink is £85 inc VAT available anywhere online. VW one is around the same. Connects2 about half the price.
If you want full iPod control from an OEM headunit buy an RCD510 or RNS510 with MDI.
Although I prefer my Pioneer head unit for iPod control over my RCD.