If your limiting factor at the moment is upper body strength or finger strength (that sort of thing), using a fingerboard frequently should improve your climbing to the point that strength is no longer an issue. Just make sure you warm up and cool down after each session, I learned that the hard way. The other good thing with the Beastmakers is that they have slopers on the top and they really help your ability to grip on slopers outdoors!
Just don't over do it!!
There's loads of threads around if you have a search with people reviewing how fingerboards have helped their climbing.
In reply to jamesclimbing: it will help no end. I have had mine since October and have gone from 6a to 6c. Just cause I can hold on long enough to read the moves. I train on it every other night. Warm up is important as said above. I go for a run. Then hang on the big jugs for 10 sec. Then 20 press ups. Some stretching. Then 10 pull ups. Shake off and begin. Down load the beastmaker app to. It will show u your progress which keeps u coming back for more. I warm down with half hour beginners yoga dvd. Feels a bit gay but are try anythink once. Haha. Buy one, u won't regret it.