I take time to compare things that I purchase, especially if the are of substantial or ongoing cost, such as an EFB is. I want to select WingX Pro because of the totality of features but there are two glaring issues:
1.) No electronic users guide. Consider, every instrument in the cockpit has a guide for its use that can be found in the POH or AFM. You can store both of them on your EFB and that becomes very useful if you have to reference it in flight. If you use an EFB and need to reference the users guide in flight for some frequently unused feature or perhaps because you do not fly often enough to remember the intricacies of the EFB, it is better to have a users guide to reference in flight. When newer versions of the EFB are released, the learning curve goes back up again. Being able to check your EFB Users Guide while flying and study it when not flying is the best way become proficient in the EFB. Access to the Internet, watching videos to find what you are looking for and trying to determine which video to watch are not things to be doing, single pilot, while flying.
2.) When WingX Pro displays the sectional, everything is fine while flying due north or if you are using the North up orientation but as soon as you use track or north up and the map rotates from true north, confusion ensues. If you fly with a glass cockpit, with a MFD, this might not be a problem but if you fly with a six-pack, or you use your EFB as a way to confirm what is on your MFD, the time wasted looking down, mentally orienting the sectional (physically turning the EFB) so that you can read information on the WingX Pro sectional, you might find yourself spending an inordinate amount of time looking down, not out. In a pattern or busy terminal area, this is dangerous.
I believe the FAA should mandate, similar to POH and AFM requirements, all portable avionics in the cockpit have either a paper manual or an electronic manual in textual/pictorial form and absolutely NO videos, like most other EFB programs. I am NOT saying the instructional videos are not useful. In fact, they are very much so. But I do not want to have to take the time to watch a video when I can thumb through an active PDF to find relevant information.
My 3 star rating reflects the importance I place on the two issues. If they were satisfactorily addressed, I would be giving 5 stars.