Is there some expression for situations where you can conclude that a solution's advantages are the same as the disadvantages of alternative solutions?
If you want to be a bit verbose and humorous, you could just repeat the fact verbatim and put the sentence as if it was a clear example/counterexample.
Example: You sell your car and do all your traveling by bicycle. That is environmentally friendly and your personal health benefits. On the other hand, shopping and quick, long-distance mobility is limited.
So you could say:
On the one hand, I sold my car. On the other hand, I sold my car!
Colloquially, we might say
It's six of one, half a dozen of the other.
It's a wash.
or more technically,
There's no net benefit.
The net benefit is zero.
Substitute other nouns for benefit at will.
Not sure if there is such an expression, however you may say that 'the advantages do not outweigh the disadvantages'.
The word I would use is balanced.
As in, "The pros and cons of the action were balanced."
kif kif, a good one is:
The front is as big as the back.
there are many sayings of this nature in English, most are mentioned in the other answers. That's my favourite one.
Well, it depends on the case.
.NET's reflection is just as good as Java's reflection.
My girlfriend's dog was just as bad as her former one.
Double-edged sword or two-edged sword.