While at OSH this year the one item that caught my attention was from Aspen Avionics
http://www.aspenavionics.com/
AT300. This unit is TSO'd for direct replacement of your VSI and therefore does not require any additional space in your panel. It has some really neat features and a very resonable price $2995.00 show special. It does require a GPS to receive the information needed.
Check it out.
Has anyone seen or used this unit?