I agree, this would be useful - although an advance feature as most user's won't know what all the DHCP options are - but Yes in my books, as I periodically need this.

Yes I need this too! Trying to use pxelinux now need to abandon dhcp from draytek because I need it straight away.

Me too please.

Big vote for custom DHCP options - Really need it for IP phones. Some might say that you should use a proper server for these kind of features but when you're in retail or hospitality you don't want a server in each of the 500 stores around the country. Only option available at the moment (AFAIK) is using DHCP relay to a head office DHCP server. Not tested it with IPSec VPN yet but looks like the only way for use on an MPLS network.

Yes i too really need this as my voip phones need a tftp server. Is there any way i can achieve this on the router?

For TFTP you can, but it doesn't support many more options than that; the command in telnet is "srv dhcp tftp 192.168.182.71" for instance