Whoops--you've done the former, I'm afraid to admit. I have Ens 4 loaded on my MacPro but don't use it. I'm sure it's great, but since I'm not using a slave computer I didn't want to take the time to figure it out. (aux tracks for automation, if using Logic Pro? Is that still in effect? I just want to click automation onto a track and go.)
I finally broke down and ordered a "new" MacPro 6 core. Will load Ens 5 onto (Mir for me finally) and use my 06 Mac Pro as a slave.
I suspect the advantages of Ens 4 probably outweighed the disadvantages, but to the unaguainted it just seemed like another layer on the onion, and I got along fine without it. Cheers, Tom