Shortfinals are a bunch of likely lads / lasses - selling their ken on the ATPL exam thing.
They have made a number of forays into the forum creating openings to generate awareness of their website. Suspicious postings from very green usernames keeping the topic to the top of the list.
As to whether they are useful beyond the service you get at BGS, OATS, Atlantic or wherever, check the archives!...But why not ask the schools if they can provide this sort of stuff if you need a bit more....you may find they a lot to help you out, including sending personally tailored help at no extra charge....the human factor, just TALK to them!
On the other hand, ShortFinals may just help you out.....so why not give them a call and ask for a free sample of what they do?
If they sell their services to you, and you get a benefit that makes sense against buying yet another textbook, why not?
Good luck,
Laurie