Get one. I have never had a problem! I suppose that if you are in an aircraft with a canopy, maybe....but I have plenty of alternative placements in the cockpit out of the sun.
I have a friend that bought the mini and he has it mounted on the yoke. One of our 604s has old EFBs that are useless and so I have just taken it out and used the mount for the iPad. Sunlight has until this moment, never been an issue. The other 604, I just have it on the side.
It permits me to have Jepp, so if I get a call, I can review the charts, the manuals etc all in the taxi to the airport (or in the house´s smallest room) I can check runways or en route charts, overlay weather radar and upper winds, low or high en route charts, I have the AFM, the weight and balance, the QRH and the MEL......and it is there when-ever a question arises, a phone call comes in, the engineers ring with a question, something comes up over dinner with the co-pilot.....we can look it up. Even better, we can search for words. Better than an index!
With AIRINC, I can calculate and file a flight-plan......there are just so many apps and possibilities. Add that I have books, so that I can read in iBook and carry 100 books with me, instead of an "real" book or two and the weight and bulk.
Have fun!