I did it last night, no issues whatsoever and it is fantastic, really, really nice. I urge anyone thinking of doing it to do so. I would say Lollipop is by far the biggest upgrade Android has had. I have know Android on Samsung Galaxy phones and "phablets" since Gingerbread on the Galaxy s2, and this makes Gingerbread to Icecream Sandwich look like a bug fix.
Seriously the device is like a new model. Is quicker, more responsive and the new look is delightful. From the new charging screen when the phone is switched off (energy trickles like a thin line of glowing been liquid from the the bottom of the screen adjacent to the USB port up to the battery which has energy shloshing about like a tank being filled - gorgeous.), to the new notifications on the lock screen. It is just superb.