In my opinion anti-decompiler is a must if you want to SELL or RENT an EA. I have a very good EA but Im having my doubts in publish it on mql5.com. First because it can be used for free for the people of metaquotes, but as I need the money and I have no better option at the moment, I have to accept that. But the most terryfing thing is that someone can just download the DEMO and decompile it, well and if they cant do it with the demo, maybe after buying the product, I dont care my EA has been decompiled and now, he can sell it and put it for free all over the internet. NOT FUN.
A anti-decompiler is a MUST end of the history.
Anyone is using a nice anti-decompiler, Im going to try this one-> https://www.mql5.com/en/articles/1572
People of Metaquotes don't care about your EA.
Any executable can be decompiled, but with the "new" mql4/mql5 compiler you can't decompile it in source code as before, only in assembler. It's really costly to do and I doubt any EA is worth the investment.