Switching from or to an old school mechanical dial lock or digital lock each have advantages, however not safe all safe locks can be switched.

In general, mechanical locks with sequence dialing 4 left, 3 right, 2 left and one to engage in pull the bolt can easily be switched to an electronic lock with digital keypad or bio-metric keypad.

Upgrading from a dial lock to a digital the following is the “rule of thumb”: 
If your dialing sequence is 3 right, 2 left and 1 right you have a "direct" wheel pack*.
You cannot effectively upgrade this lock.

Upgrading from a digital to a dial lock depends on the safe you have purchased.

Dial locks last the longest, however heavy usage will wear parts. The lock will need service and combination reset.

Electronic locks are durable. Sadly, keypads and electronic components fail, and at times, abruptly. 

This circumstance can lock you out and it's recommend changing the electronic lock between 8 to 10 years no matter the frequency of use.

Dial locks get difficult to open when certain parts begin to wear.

This circumstance will cause accuracy to drift and at times you will need to dial the combination multiple times before the lock engages to open.

* . A safe with a direct wheel pack has a “stub” attached to the locking bolts will slide into the “gates” in the wheel pack.