I have a SA subscription, Skyview 7" displays and Skyview autopilot. I also have a MacBook, running VMware Fusion (using Windows XP) to access and download the SA VFR Sectionals, IFR approach plates, via the SA Chartdata Manager program.
The sectionals I download from SA are the newer, high resolution type. In order to use that, the Skyviews must be upgraded to Skyview system software version 13.0 or higher.
My primary navigation tool is my iPad Air. It is awesome. I fly a high-wing airplane (CTSW), so the glare from sunlight is not too bad, as in most low-wing airplanes. The backup navigation preferred is the Skyview generic. After that, I use the SA sectionals. I find the sectional maps to have a somewhat, "washed out" appearance, as compared to iPad and Skyview generic maps. Therefore, I rarely look at the sectionals on the Skyview while flying.
Bottom line, I do not think the SA charts are worth it. With Mac users, they are a PITA. First, you must set up the computer to handle it. Secondly, the downloads are extremely slow, especially compared to Foreflight, WingX, Jepps and Garmin. Downloads with them, even with much more data, are a flash.
Lastly, Seattle Avionics is not interested nor has any plans to upgrade their site to be natively compatible with Apple products.
On a final note, I have found that SA's tech support is, at best, mediocre. Competitively, the company is behind by years.
When my subscription comes due for renewal, I will let it expire.