Yes, it is true. You have to reprogram the ECU after this change in order to reflect the correct reading on speedo (But a slight speedo error is still there anyway).
not the right place to ask this question,
but , yes, there may be some error / difference of speed in analog and digital.
its obvious that they (OEMs) try to make it as precise as much possible, but there will be some difference. you can compare them with GPS speed on highway ( with someone sitting on your left side to prevent any unexpected )
@Navneet - Its the poll for which one is VALUE FOR MONEY. Right?
It's obvious that Alloys are better-looking. Better looks are standard in alloys for the extra bucks you spend.