Given the nature of the spell Comprehend Languages in Pathfinder, is there any particular advantage to taking Linguistics for a character who can cast it? Especially given the chance of severe (or horribly entertaining, depending on your point of view) failure with Linguistics that doesn't seem to exist for Comprehend Languages.
This has come up in one of the campaign I currently run. Comprehend languages, like most spells, has a limited duration and is therefore only useful as long as:
Of course, players could prepare the spell more than once, but then they find themselves short on spell slots. Charged magic items can offset the disadvantage of spells without requiring slots, but they tend to have a worryingly large up-front cost for a non-guaranteed payoff.
The problem with translation spells is exacerbated by the fact that memories are rarely perfect: A wizard who read the riddle-poem of Llasynt the Long-winded probably won't remember it word for word, and if guessing the password for Llasynt's front door requires the third verb in the fourth insulting stanza, then he'd better have made some detailed notes...
Linguistics, on the other hand is always on, is non-magical (and therefore works in situations where magic would be impossible, inadvisable or a social faux pas), and makes you a hit at parties. It also doesn't require you to touch the target for it to work, which again may allow you to avoid potential hazards, inconvenient distances, and more social faux pas. Plus, it grants you an additional language known with each rank, which is a nice way to avoid making mistakes with the skill entirely.
Our brave band of fearless heroes have braved the Chasm of Doom, crossed the Bridge of Tears and found their way to the Orc lair, from which they can make out some grunting in the fiendishly difficult greenskin tongue.
"What are they saying?", whispered Mik Half-finger.
His elven companion smiled and spent a few seconds incanting.
"They are saying…"
"Yes?", prompted Mik eagerly.
"They are saying that someone is casting magic behind this wall."
"Then shoot them with a magic missile!"
"I can't! I memorised Comprehend Languages this morning!"
Comprehend Languages requires time (sound, spell components, etc) to cast and uses up a spell slot.
And since the problem will arise, what about Linguistics vs permanent Tongues, or an equivalent item? Basically, the thing is that one of the often forgotten points of Linguistics is that it is not useful only to speak/understand a language. It also represents how deeply you understand this language, etc. It can be seen as Knowledge: languages from this aspect.
For example, someone with Tongues/Comprehend Languages would be able to speak/understand French, sure. Ask him for the etymology of one word, and he is screwed, he just doesn't have the knowledge at all. On the same note, he probably has no idea how the grammar/conjugations works. It also mean that if he encounter some kind of slang, he won't be able to speak it, as he has a global understanding of the language, not of his workings/adaptations.