Z11 Pro Max is amazing. It's super slick and does the job well. Only gripe I have is it doesn't support DolbyVision so no good for using it for plex...
I hated the shield pro, tried to like it, but its just too sluggish and the "ads" are annoying!
So, for me, the shield is back in the box and I use a mix of:
Apple TV 4K for general usage
Z11 Pro Max for IPTV when I want HLG support (iptvx on the appletv does this SOMETIMES...but its still buggy..)
Z9X Pro for proper dolby vision playback
Annoying using 3 boxes, probably don't need to. If I had to chose, the appletv 4k does most of everything I need!