My friends and I have eaten at Carnation Cafe a bunch of times over the years - I can't even count how many times because we started going there back in the early '90s, I think, when the menu was very different and when there was inside seating as well as outdoor seating. We seem to now have a Carnation meal (sometimes two) on every DLR trip, so just since 2007 alone we've probably been there 6 times (over 4 DLR trips). And we also have done breakfast, lunch, dinner
and dessert-only at Carnation.
Now, all of that said, I will definitely recommend Carnation Cafe to you

while saying I am personally a bit burnt out on it. The menu is good, but it is limited - especially in comparision to what it used to be years ago. A lot of the reason we have continued to go back is because it's familiar, it's habit, one of my friends really likes it, etc. But I could have stood to skip it on the last DLR trip and try something else. I think Carnation Cafe has a lot of quaintness and charm to it. It's a perfect location for people watching (and sometimes parade watching) - in fact, one thing I did do in October was request a table alongside Main Street, instead of getting put in the back or on the side of the restaurant where we normally are and can't see anything. Of course, it took much longer to be seated while we waited for a Main Street-view table to be cleared, but it was a great spot to be in once we sat down. That's the other thing, though - the seating is
very limited in general so a line forms rather quickly with people waiting for tables. In fact, the people in line waiting can look right down at you while you are eating (the line is right next to some of the tables), which is always awkward! I think making a PS for Carnation is essential, because whenever we have gone there without a PS, we have waited a long time (once we waited about 40-45 minutes). Sure, they must have slower days here and there, but I wouldn't risk doing it without a PS again.
As for the food, I think we established we like Carnation better for lunch or dinner than for breakfast, but it's all pretty good. The meat loaf stack is great (usually). My friend got sick from the pot pie, however. The dessert meal was great because a few of us ordered the apple pie a la mode - which comes with, of course, ice cream, lots of whipped cream and a couple of strawberries sliced to perfection - and the Matterhorn sundae and shared them between all of us, along with some coffee drinks, and watched the part of the parade that we could see. We have also seen a giant bowl or dish of something ice cream-y sail past us and onto another table, and I am not sure if it was a banana split (they serve those too) or some other evil concoction. Whatever it was, it was ENORMOUS, and everyone in the restaurant pointed, stared and gasped as it made its way into the hands of the young couple sharing it. (They didn't even get through half of it, by the way.) To this day, I still don't know what that dessert was, but it was big enough for four people.