For the record, Tim Powell and I bit the bullet and purchased an HDS 8 with all the trimmings and installed it on the boat when we were in Charleston a week ago. We only got to use it one day before we left to return to the frozen north of KY but it appears to work very well. Two Saturdays ago, we ventured out past the Jettys about a mile and then back close along the inside of the north Jetty and could see quite a few details with balls of bait fish in sharp detail and various other structure. With the HDS 8's screen size of 8.4", you can view a generous sized split screen of the downscan and normal sonar and get a couple different views of the same image. Or you can divide the screen into 3 or 4 windows and still get enough size to see what is happening. We will be back for a week starting April 23 and will give some more info and pictures. We bought it from West Marine and also purchased the two year extended warranty (4 years total) so they have to send someone to our boat to service it. Most of the recent reports indicate that Lowrance is doing a better job of servicing their product. They did match the best price on the internet plus gave us 10% additional discount. We also bought an external antenna for the GPS and mounting it near the transducer. The preloaded Insight maps show outstanding local detail around the Cooper, Wando, Ashley, and other areas. More details and some pictures in a few weeks after we figure out how to use the silly thing.
Big Woods (now known as the Lowrance electronics guru after laying on my back scratching my head for several hours installing the unit)
Thus far, I like my HDS5 as well. I did not go for the structure scan options but may consider adding that feature later (or buy a separate unit later). The only thing I do not like is plugging/unplugging of the system (gimbal mount).
By the way.... why would you install an external GPS antenna near the transducer ? Am I missing something?