I have a humminbird 798ci. It has great sonar and lots of bells/whistles, but i've found that the computer is very slow in updating the gps/map location when moving around, depending on the depth line resolution and colors. The more resolution, the longer it takes to refresh, and the screen can go blank for 15 seconds when really moving w/speed. I think the 998 is probably a better board. I'd like to upgrade once i can afford it. Not sure if the side-imaging is all that necessary for most situations, once you have experience reading the color graphs. I could probably use it but can't justify the cost right now.

I'll also say that the GPS-determined speed on the 798, and from what i gather most HBs, is iffy at trolling speeds-- often have to ignore what it's reading and just watch the wake that the planer boards are making or the angle of the drop lines. Don't know if this is the case with other brands.

Gander mtn has the 798c HD w/ side imaging for ~$650 right now, not including a rebate-- i think HB may be having a promotion?

They have introduced the 99 versions of most models now and the 98 are getting reduced to clear the inventory from what I can tell.