Happened to be at the pilot shop in Orlando yesterday & saw one for the first time. Was not impressed.
Large, cumbersome & slower to use than a pencil & bit of paper + looking at the DI to gauge w/v vs runway direction.
Nothing on the device seems to lock any of the myriad wheels to any particular position. What happens to your settings when you put down/in a side pocket/in your nav bag/wherever - and the awkward thing gets bumped?
My judgement: A WOFTAM - and only more efficient than a pen if you're illiterate.