We used them at PHI - all the medium and heavy aircraft had them and they were implementing them in the single-pilot single-engine ships.
My experience with them was great. Aside from figuring flight planning, take-off and landing weight and balance, fuel burns, and performance planning such as max gross weights, HOGE, etc., it was a great tool utilized with the comm center for the company. Since there is little radar and flight following must be accomplished with the company in the Gulf, they were tied directly into their network and our Outerlink SAR system. When we took off, the EFB knew it, recorded take-off time and armed the Outerlink. The comm center then could track the flights in their version of 'mission control' on a big computer screen and knew exactly where every aircraft was at any point in time. The other major benefit was the ability to send messages. Many places in the Gulf lack communication capability, especially on the deck of an oil rig. We could utilize the EFB to message the comm center of our landing time or to pick up an IFR clearance for us from Houston Center which they would message back to us. It allowed us to keep the aircraft running, hot fuel and load, get the clearance and be on the way vs. shutting down, descending 3 or 4 flights of stairs and trying to make a phone call to center when the weather was too low to depart without a clearance.
The other nice thing from a pro pilot standpoint was at the end of the day it printed out the entire flight log and takeoff/landing times and total time for the day, IFR, night, X/C, etc. Great for billing - just faxed that sheet to the business office, and also a nice verification for my logbook.
In the single pilot ships it was a bit busy, but in crewed aircraft it was quite helpful. Outside of the Gulf I'm not sure it would be much more than a nice toy.
