Score: 5 out of 10 (Yet I won't NOT eat there.)  Here's what I think of Souplantation:

It's a food orgy for the elderly and pseudo-health conscious.

The salad is plentiful and there are a good amount of options. But the options are never exotic or edgy.
The pasta is bland. No matter what, the pasta is always bland. It doesn't matter WHAT pasta or when the pasta was made, it has a blandness that is blandtastically blandy bland. It's fucking bland. I'm sorry. I don't know who decided that Souplantation HAS to have bland pasta, but dammit it is.
The soups aren't even mentionable. It should really be salad-plantation. Because if it was a SOUP Plantation, in the old south. It would have NO slaves, and NO crops. Just three soups. It would not be successful.
The hot baked foods? 3 variety of muffins, cornbread, and some chocolate cake thing. 2-3 pizza-like baked goods sliced in stick form.
Dessert? Pudding or Soft Serve with toppings.
Seriously, it just seems so lacking.

And yet I've eaten there at least 3 times a year. For 20 something years.
I don't love it, but I've never eaten there on my own dollar.
Oddly enough, I don't hate it. I should hate it. It's a glorified salad bar.
But I don't.
I can usually put together a somewhat edible meal.
I usually get full.
I usually eat, till I can't. I tend to get eaters remorse.
This consistently mediocre restaurant has had years of my business, when I have never had to pay.
Why?
My sister loves the place.
We never talk about how freakin' delicious it is.
In fact, my family has never once complimented the quality of the food.
It's bizarre.
But my sister insists on taking us there.
And there we go.

Oh yeah, and how do I know it's for the elderly and pseudo-health conscious?

NOT ONLY DOES IT SERVE Diet Coke as one of the fountain drinks... it also serves CAFFEINE FREE Diet Coke.

Seriously.