I've done both. I now no longer use windows mapped drive letters ... because with windows 7, and an SSD boot disk and use of sleep not power off, usually the PC and OS are booted and trying to access the LAN, *before* the NIC and IP stack are working and have finished DHCP. This causes the mapped drives to show red X's in the drive "computer" display in windows. (My PC resumes in < 5 seconds). Using a static LAN IP for the PC helps too - no DHCP delay.
Instead, I use shares with the network addresses: \\nasname\sharename.
Just lately, I found a cure for the too-fast-boot problem above. You run a little batch file after a 15 second delay, or so. In that file are OS commands to re-do the drive mapping. This is a real hack. Microsoft has known about this for years and, like so many other bugs, ignores it.
I put the file in (win7 64 bit)
C:\Users\myusername\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup
the .bat file contains this inelegant code for two drive letters:
echo C:\Users\myusername\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\netlogon.bat
@echo off
ping localhost -n 1
net use Y: "\\Ds212\y2"
net use Z: "\\ds212\Downloads"
ping localhost
the ping command also causes a time delay.