Best to look on a site that bases their comments on actual research, not just opinion, like www.kellymom.com or the La Leche League International site. Off the top of my head, I would suspect that the immunological properties of the milk could be reduced if you freeze it, and possibly some of the physical properties (freezing even cows milk can disturb the way the fats and proteins are arranged) but the overall nutritional make up, in terms of the proportion of fat, carbohydrate and protein, won't be changed. So basically it's crap.
And I completely agree that the Baby Whisperer is of limited help with breastfed babes. For example, the 'dream feed' just didn't work with my two - unless from a bottle (has anyone ever managed to breastfeed a baby when the baby doesn't want to??). Plus she makes several comments that colic is not real, just a result of an inappropriate routine. I'm sorry, that's complete b**ks. Ds2 screamed the place down because he had severe reflux, and ds1 because he reacted to the slightest trace of cow's milk protein in my milk. Once we'd worked out what was going on, the 'colic' disappeared. Not related to routines at all.
The reactions to cow's milk are the other reason why I would always prefer ebm, frozen or not, to any kind of formula - I know what has gone into it! Even the elemental formulas made for severely allergic children are based on cow's milk, and soya can cause the same reactions in children sensitive to cow's milk - and did with ds1 because I tried him on soya formula before I knew any better. Several reasons why, in our family, formula is not allowed through the door, although I know that in other families it is extremely useful.
I'll get off my soapbox now! but if you are thinking of using ebm, it might be worth checking how long it lasts in the fridge, because I used to be able to keep mine for about 5 days without having to freeze it. Again, the info should be on kellymom or LLLI.