Yes, I'm running true Xenons. They take a sec or two to fully light up and shine like really bright, concentrated fluorescent lamps. The main lamps are only low beams. I use the driving lamps as high beams.
At the end of the day, I guess I'd be willing to sacrifice a bit of HP to get a true all around car that is still seriously quick and fast. Besides, I could always shutt off the stereo and the airconditioning if I need to get back the few errant HP.
As to your head unit questions, I always found Nak's top of the line offerings to be truly amazing products. I used to use Naks until they started having quality problems. I turned to McIntosh for my car audio requirements. Nak seems to have gotten back on track and was therefore willing to give it a second go. On whether to get the CD45z or the TA25, I guess that would depend on what you are trying to achieve.
The TA25 is a tuner/amplifier only and does not have CD functions. Getting a changer would bring up the price by another $500. The CD45z has a built in single disc player.
I tend to subscribe to the philosophy though that you should by the best you can afford, otherwise, it just costs more in the long run (upgrades, selling used ones at a loss, etc.) In my case, I think the TD1200 is overkill. The CD700 while expensive, would provide excellent sound. It has (one of the) best mobile DACs currently offered which can even perform DAC duty for the music bank changers.
An added bonus: it keeps the stock look as it almost passes for the OEM Becker unit
A *slightly* less expensive alternative is the McIntosh MX403 which has an amazing DAC as well which, like in the CD700, can be used as a DAC for McIntosh's CD changer. It also has that cool classic signature McInosh look to it.
Hope that helps. Feel free to email me if you have any other questions.