well......
I have worked my way through a fair number of GPS units. I had 196 then a 296 and now a 496 as well as a couple of the PDA solutions on the way.
The 196 is a cracking unit, clear display and good battery life but not rechargeable. The 296 is another league compared to the 196, crytsal clear display and fantastic battery life. I did home to Menorca and back in the twin without recharge 13hrs flying. The 496 is a great bit of kit, faster screen draws and nice presentation of airspace using the smart airspace feature. Is it better than the 296? Well to be honest probably not, I bought mine on a bit of a whim and to be honest it does little more than the 296. Now if I was in the USA it would be a cracking bit of kit with the XM weather.
I have tried a couple of the PDA solutions and not of them had the reliability or ease of mounting that the Garmin kit offers, I don't like Yokemount stuff the garmins sit on the dash and the PDA's were unreadable at that distance. Also the battery life really sucked, OK for a bacon butty run but 5hrs to Perpignan and they were flat. I also found in the airways they misbehaved, uncommanded shutdowns etc which may have been pressure related.
My view is buy a 296 if you can afford colour or a 196 if not.