Camshaft & Crankshaft Sensors '97 528i

I have problem with Camshaft & Crankshaft Sensors. Bad start when cold, slow acceleration (sometimes). In BMW service center they told me that these sensors have to be replaced.
How critical it is and do I really have to replace them?
Thanks,
Farhad.

Well, Farhad, I didn't see this post when I responded to the door problem so you have ready access to a BMW center. While it's possible that both sensors are failing, the most common is the cam sensor[s] depending on DME level. They should present you with the diagnostic print out which will show component, last failure, failure history, fault's status, ect... There should be no doubt on your part and it's easy and quick for them to supply these printouts.............................jeffb.