The way I see it, Untitled gives you two essentially useless adventures, one adventure with a chance for some nifty bonuses, and one with a chance for added rep.
Magic Mushroom yields 1 energy on average, cancelling the 1 energy you paid. You get EXP, plus career exp if you have that on, but every adventure gives you that, often without paying 500 GC. Grammar Pill is the same, except you get no energy back (and I agree that it only hurts you on the Typing test).
THEIF is a fairly easy 3 rep if your Stadium skills are upgraded (like mine). Once you’re at 90%, you’re paying 500 GC for 2.6 rep on average. If your Stadium skills are minimal, it’s 1 rep on average.
Strange Machine is probably the biggest reason to go to Untitled, depending on what you want. If you break the machine, it’s 30000 GC, -1 energy, -3.2 rep average. If you pay with intent to drink, it’s -1 GC, 200% all boosts, +0.25 energy average. If you pay with intent to sell, it’s +1 GC, 2 rep average.
(This illustrates how going full negative on rep can be a benefit: some adventure paths become a lot more attractive. You could break Strange Machine for GC with impunity if you want to farm negative rep as well. If you’re positive, you’re probably going to drink for boosts.)
So to repeat, Untitled is basically trading 500 GC for a slight chance at more rep, and more boosts or GC… plus a bit more player EXP, 10 more career EXP, and 120% as many adventurer trophies (good if you’re affix farming or selling them off for pixels). That’s the entire tradeoff AFAICT.
Titled is worth it if and ONLY if you have a fair bit of one type of thing and need a fair bit of a different type of thing and don’t mind taking a hit on the transaction. It’s for traders, in other words. Arcade tokens for 100k medals; fertilizer types for rep/BC; GC<—>BC; pixels<—>crafting mats; keys<—>treasure boxes; and finally, GC for more GC if you’ve got hundreds in gem capacities on LolMarket (is that even possible?). Plus you’ll get slightly even more player EXP and slightly more trophies.
I transcribed Draconi’s guide to Wikia and put it in table form, in case anyone finds it helpful.