Humminbird 1100,s question

A question for the ones that have had these bigger units in the past. Other than being older how much difference is it between the 1197, 1198, and the 1199 humminbird units. Are they a whole lot of difference in the SI pictures. Would like to know what anyone can tell me about these units. Seems like other than the stuff like monitoring the boat motor, 360, and linking to trolling motors they seem to all be just alike and I really don't need them. Will all of the ethernet to my HB 899 unit also. Thanks for any and all help with this in advance.

http://www.humminbird.com/Products/1197c-SI-Combo/

http://www.humminbird.com/Products/1198c-SI-Combo/

http://www.humminbird.com/Products/1199ci-HD-SI-Combo/

I still have an 1197 and a 1198 and still like them. The new mega units are a game changer with the SI and DI clarity. The biggest difference between the others will be processor speed and to some extent the brightness ..... the brightness level took a big leap forward with the first generation of the Helix ... and the 1198 is the first with the LED backlit display.
There will also be a difference in what accessories that are supported.

I have a 898 and 899 SI, the biggest difference between the two I have is the 898 dose not have a internal GPS antenna. I also don't know for what reason why but to network them I had to buy an adapter. I will say if you purchase make sure you get the HD transducer way better images. Also, I found out after I purchased these units, to the tune of $1100 plus accessories, the DI is a composite of the SI image, not a true DI image, of which I have noticed I can't see whats truly on the bottom. I have a Lowrance 5" unit that is DownScan and I plan on putting it back on my console just for the DownScan image... I was uptset to say the least when I found that out about the HB's. I can't say I know that about the 1100 series.