I don't know if duct tape would be a good description of CoH, I would probably describe CoH as the "Front Wheel Drive" of MMORPGs.
The reason I used Duct Tape was because of a Myth Busters episode where they were put on a island (Gilligan Island style) with a pallet of Duct Tape as their only item.
From that Duct Tape, they made:
beds
Shelter
water containers
chairs
netting to catch food
a fishing spear
an outrigger with paddles
clothing
a devise to start a fire
bags to carry supplies
They determined that Duct Tape was the single best item to have. Although there are other items that do specific jobs better, Duct Tape does pretty much everything well enough that it is, overall, the better item to have with you. Much like CoH.
There are other programs that do chat better. I like the smilies in The Realm Online, CoH doesn't have that.
there are some parts of the costume creator in CO that I like better than CoH. Although, I like CoH's graphics better.
The Secret World has better graphics than CoH, except for the fingers. Those guys have some freaky looking fingers.
Those are just a few of the things that, in my opinion, other games go better than CoH. However, taking each game as a whole, I prefer CoH over all the rest.
Now, there are a few things that I think CoH did better than any other game out there, that I've played. Such as Teaming, and the global friends list.