M5 Navigator System Problems-Any Suggestions?

[UltimateM5]

The navigation system dics reader on my 01' M5 recently died on me. My dealer was clueless other than to offer me a $1350.00 replacement. I had several electronics shops tell me the same. My dillema is the system (Phillips) is a bit outdated ( entering a location can be quite time consuming) and there are much better, more updated systems out today that cost about the same. Pioneer's touch screen model is a killer in comparison. The rub is, of course, I would loose all the functionality of my TV/DVD/Navigation/M-Sound Stereo combined with all the car's computer output, if I choose to go with an updated stand alone system. Not to mention the issue that there really isn't any space to accomodate another unit with a seprate touch screen in the M5 dash/console. Has anyone had any experience in upgrading the navigation system in an 2001 M5? Is there a chance that the latest (2004) BMW factory installed navigation system would be compatiable with an 01 M5? Any suggestions?