I have that exact same tint on my '09. Although we don't have much of a worry about heat up here (I'm also in WA), I have noticed this winter when the temperatures are dropping, my car takes longer for the windows to frost over. I get off work at 10 or 11pm and most of the cars around me are all frozen over. I have yet to scrape ice off my windows. Only con that I know of is the extra cost.
'09 GS350 SGM - JoeZ Intake - Tanabe Exhaust - G2 Blue Brake Calipers - F Sport Sway Bars - Tanabe NF210 Springs
I'm running 20% rear, 50% driver and passenger, 5% moonroof and windshield visor. I know I like it this dark in CA, not sure if I would like it in WA. Depends on how much sun you get. I really don't like this carbon based tint I have now. The heat reduction isn't near as good as the ceramic I had on my Cadillac. I'm definately going back to ceramic next time. I don't have any pics to share right now. Sorry.
For the longest I've been put off doing tints because I don't like being pulled over by police occifers, but we have a little one riding in the back now and I'm thinking if going with 50%. Maybe in spring.
92 Lincoln Mark VII LSC
06 Lexus GS430.
I currently have 30% non-ceramic all around. Planning on replacing just the rear sides and rear with Llumar CTX Ceramic 15%. 5% limo is too dark for me but 15% will give me the protection and privacy needed in the Texas sun. Went to two reputable shops and both about $360 to remove and retint.