Yeah if you already have jb4 it's probably in your best interest to run a bef. Otherwise people are selling their jb4s all over the place so if that speaks anything to you. I personally run mhd and have never experienced jb4 but from what I read I think the jb4 the logging parameters are better and map changes are easier and there's not much to be afraid of like there is when flashing mhd. A friend of mine was jb4 and got mhd. Idk if he's full mhd now or bef but I'll ask him.
I've tried just MHD and, I was impressed by how it behaved on just a DME Flash but, I have tried using the BEF + JB4 and fell in love with the combo. Bluetooth parameters displayed on my phone. Logging doesn't cost 100$ for a extension on to an app.. At the end of the day youre gonna drop 200+ in a tune anyways. Might aswell get the best setup you can. Plus the JB4 can prevent damage in ways the MHD alone will not.