Whether or not you should use a protein rest could vary from lot to lot of the same grain from the same brand (although most maltsters spend a lot of money and effort trying to get their malt as consistent across lots as possible.) The only way to really know is to read the malt analysis sheet for your malt.
Here's a link to a good explanation: http://brewingtechniques.com/bmg/noonan.html
"For all-malt beers, protein values exceeding 12% (1.9% TN) indicate that the beer may haze or present mash runoff problems. European lager and British ale malts are usually below 10% protein."
So your MO is almost certainly below 10% protein, but if you were using it in conjunction with other malts with higher protein that could bump the total amount of protein in the grist up to the point it may
be less that optimal.