I would go with either Amiko or the z8 pro all people go on about for the shield is upscaling nothing more fact.
Another couple of devices to consider is the buzz range like the vid stick or XRS4500 which our forum sponsor sells kuul media the remote to the shield is just like a firestick remote.
My shield is setup for gaming nothing more and the z8s and buzz range are highly supported on the forum
Apart from the Gaming aspect and the A1 upscaling it also works flawlessly with smart hub with home security cameras in my case!
The only similarity the Z8 has compared to Pro shield is the shape that Formula seems to have stolen from Nvidia! Probably making them handier for door stops