Welcome aboard the forum, J and V. I've had an ABII-5 since November 2006 and never looked back (I put my '76 P bass up for sale right away). I occasionally play my emergency back-up bass, a MM Stingray 4, but use the ABII whenever possible. It plays so well (low action, even tension, great electronics, more tonal combinations, etc.) and getting used to the fifth string hasn't caused me much trouble (the ABII is my first 5er). At first I approached the 5 differently -- choosing lower registers for certain notes and songs -- but have since become very comfortable with playing it as a 4+ stringed bass, if that makes any sense (good muting technique helps a lot). I don't do a lot of slapping but when I do, I prefer the ABII. I'm constantly amazed by the great sound, quality construction, design and support -- from Sheldon, Dingwall Sales and fellow Dingwallers - a very generous, inquisitive and innovative group to be sure.
I originally set my sights on a Z and didn't want to order one w/o first finding out whether or not I could play the fanned fret neck or whether or not I liked the sound. I made two 4 hour round trips to the nearest DW dealer, who happened to have an ABII -- as it turned out, MY ABII. After playing it I couldn't imagine being without for 2 years while me Z was in the queue, so I bought it on the spot. I play in active and passive modes and experience lots of that great Dingwall sound with either setting.
Hope this helps in some way. Enjoy your new bass!
John