I installed the M80s on my Malibu 182 (pretty much the same as your DE only I have the soft top). I will echo what everyone has ever told me...wish I had done it sooner. While I would have preferred the M120 as a bigger tab is better, they simply would not fit with my current kicker configuration and I was not prepared to change it as it works well. I love them after 4 months of use, great for balancing load, getting the bow down when the seas chop up, changing angles when traveling across waves etc...
While I could not find the extra $$ for the indicators, I can certainly see their value (tho I just tend to go by feel).
Bottom line, I think you will love having tabs on your boat. Oh, and install is easy. Great investment!