I would consider implementing MPLS if I had multiple sites (ie: 1 HQ + 30 Remote offices). Reason being is because you have to consider cost of implementation and the reoccurring cost it takes to maintain. Since you will be looking at probably 1 T1 at each site if not more at some sites. Like our situation we have 2 DS3's (1 at 2 different locations) + a few sites that have multiple T1's bound together, it just depends on what you are attempting to do...
The purpose of our set up is for redundancy, so if one site goes down, the other sites can still talk...
------------------------------------
Dallas, Texas
Telecommunications Tech
CCVP, CCNA, Net+
CCNP in the works