The biggest problem was the initial learning curve. Also, a lot had to do with the pilot's input to maintenance when writing up a squawk. The EX is much more precise than the B in many of its systems. A pilot must be highly accurate when describing a problem to maintenance. If pilots experience something, they can now push an event marker on the dash.
Maintenance can then download the event with all the parameters to solve the problem.
Maintenance as well as the CFO will like a lot of the warranty programs. Compared with the 900B, many of the 900EX's program-covered parts and labor have extended times and cycles. Hot sections moved up to 2,500 hr and core inspections up to 5,000 hr. All told, this provides a highly attractive warranty program. Some will elect to save the money as the 900B will cover most trip requirements with ease.