The interface of silabs was very user friendly, it has been easy to use since I got my first lesson from their support team about how things work with this software package! They are always willing to help you out if needed!! It's so much easier than keeping track manually using excel or other programs that cost money after awhile when there could be cheaper alternatives available like what they offer here at least as far as price goes (free).
Sometimes we have problems logging our results through them but usually once explained everything works fine again no problem solved yet though i am sure will do eventually because these guys want us happy customers not just satisfied ones :P.