So, we've had our little gripe session (http://www.flyertalk.com/forum/showthread.php?t=779243) about farecompare.com (which I have certainly joined in on). However, there are still useful tools that FC provides that I like to use in putting together MRs/regular trips. My favorites are being able to sort by CPM:

http://www.farecompare.com/search/flyertalk.html

and looking up the fare bases (and base fares) for different airlines and routes, such as:

http://www.farecompare.com/flights/-UA/-PIT/-FRA/schedule.html

As far as I can tell, neither of these tools are clearly advertised on the FC website, which leads to the point of this thread:

Are there other FC tools that you find useful for MRs? If so, what are they, and how do you use them?

I like the interface frankly. I love how it blots out the locations, even though I am a walking atlas :)

It's a 50/50 thing. I mean, I use it for ideas. If I see a fare that makes my eyebrow raise a bit, i'll go elsewhere and investigate it.

I've also found fares on sites much lower than on FC so it's always hit/miss.

I've used FC i the past a couple times but I've NEVER gotten the fare that they initially showed. Never ever. Makes it quite useless. :(
It COULD be a great tool though. Anyone an idea why they can't seem to display valid fares at all?

1, UP fare listing - this is an unique feature of FareCompare
2, Early fare alert - everybody (including airlines) can find deals (mistake fares)
3, Raw fare data - this is valuable for some

jackthebox,
I have no idea what your paticular issue is, but this thread might help you

FareCompare: Why is it never right?
http://www.flyertalk.com/forum/showthread.php?t=680885 (post #5)