Linux: difference between using autofs with NFS and just using fstab

This is all feasible with udev. Have a look at UAM, which seems to address most of the issues you've mentioned, but actually does mount automatically. If you like, you could make use of the great capabilities it provides, but modify it so that the media are not mounted automatically. You could also contact the author and suggest your non-automatic mounting approach as a new feature. Meanwhile, have a brief look at its capabilities:

• It works on top of udev, making it DE-independent and event-based. (It also suggests a workaround for optical media that might not be spotted by udev.)
• Lets you define MOUNTPOINT_TEMPLATES that can solve the naming issue you've mentioned in a number of custom ways (see uam.conf), potentially also using LABEL (as you desired)
• Notification mechanisms are supported, you'll just need to adjust them to your DE-specific needs.
• It seems to have a clear design, letting you easily locate where, when and how each action is triggered.

Autofs , is auto mounting filesystem on demand like when ever you need it.

NFS is like mounting a complete partition remotely and you will have availability of whole content of the partition.

But there are few advantages with autofs over nfs

Advantages of AutoFS

1 Shares are accessed automatically and transparently when a user tries to access any files or directories under the designated mount point of the remote filesystem to be mounted.

2 Booting time is significantly reduced because no mounting is done at boot time.

3 Network access and efficiency are improved by reducing the number of permanently active mount points.

4 Failed mount requests can be reduced by designating alternate servers as the source of a filesystem.