Humminbird question

[eyecatchin]

I have a 1197 and 1198 humminbirds on my boat, both were on the boat when I bought it two years ago. I have never done any upgrades to my units because I don't want to mess them up. Will it make a big difference to add the upgrades or am I better off leaving them alone? Also, how hard is it to add the upgrades? Thanks for the help.