Hopefully you got a bit of milage out of the 898si. they were great units back in the day "which sounds crazy saying that, for back in the day in marine electronics world is like... yesterday" still, up from the ashes!
Helix8 much like your 898 is a pretty solid little piece of kit. effectivly the same operating system "albiet with some tweaks" to your original unit. now running mega imaging side/down scan sonar and dual spectrum sonar. the quality of the fish finder is considerably better than the 898. the mapping side of things.. much of a muchness. So the benifit of the helix is that it has basically no learning curve... dead easy to pick up considering your previous model. could even reuse the power cable
Another consideration would be the raymarine elite range. these do embody some of the old school hbird principles of being simple to operate with a crazy high quality screen. with some of the funkyness of 3d sonar "meh.. its okay". its traditional and 1.2mghz side imaging is however rather good.
Moose