Using the Shimano Nexus internally-geared 8-speed hub on any trike gives you the enclosed reliability of planetary-geared hubs, but it's a bit slim on gear range -- particularly with a small 20" wheel on
In a sight that's becoming quite common at the shop these days, some bluebirds tried out a Catrike 700. [In reality, only one bluebird tried the trike while the others watched.]
He liked the color and the lines, but found it too difficult to shift. Also, the headrest was too big.