Garmin 500 series and 640 GPS

[horsemel]

We are still evaluating GPS chartplotters and have decided that we like the Garmin line.  I see where some of you have the 500 series and would like to know your opinion on the screen size, ability to view the screen in bright sun with polarized sun glasses and ease of operation.  We have also been looking at the new Garmin 640.  A bit pricey, but wow is it nice.  All touch screen operation and also the ability for dual use in the car.  Much larger screen and higher resolution as well. Anybody used or have the 640 and what is your opinion?
Mark Mueller

[Ron Hill]

I've got the 545 hi resolution screen and love it!  No problem with the sun light and Easy to operate. 

[waterdog]

Have the 520s.   Screen size is just fine.  Resolution is great.    Polarized sunglasses - not so much.