Lee
What you say here is true you can get a great system installed, but at what cost? Does it cost the same as the HK option does? As I don’t live in the UK I don’t know what the price of the HK option is. But your system should sound better. It costed you 1500 pounds plus I am guessing you installed yourself, which this cost needs to be thought of too.
As for using off the shelf components. I don’t if they do or they don’t, but what I think you are paying for is the R&D that has gone into choosing these components and setting it up in the car. Staring to sound like a custom install. I don’t many ICE installers that would (or could with out adding extra components) balance out and set-up you’re new ICE for free.
As you say car stereo is a personal thing, some people listen to Rock other Rap or any other kind of music. Some like so much bass that your guts are shaken so much you want to be sick. So when it comes down to it the owner of the car will have to decide if that H/K option suits his/her listening tastes and can they buy a system comparable or better sound and at a price they are happy to pay.
This has been discuss many times before hear and in other places. I have provided a link to the best words I have read on this whole debate (to date).
H/K debate link