One niggle is battery life. I've got nowhere near the expected 16 hours from a set of batteries yet. It is all too easy to waste them through inadvertently turning on the backlight. I've worn gloves for all the walks I've done lately because of freezing weather and the buttons have been hard to find. I also miss the bleeper from the 12XL which would warn me when the batteries were about to expire.
Further information is available from their web site.