Thought someone might be interested in the differences.
Interestingly the Three branded device seems to expose bridge mode which from what I've read is normally not enabled in the UI, but as its from CEX I have no clue of its history.
Notice the strong 5G signal on Vodafone (5G SINR), yeah I'm right on the edge of that masts range so surprised it even sees it. Needless to say I'm fairly sure its NOT using 5G data.
Annoying caveat, if it sees 5G, even if its too weak to use, it locks to that mast. I had to turn off Auto Network Selection and force it on Vodafone 4G to get it back on the mast across the road from me but so far I haven't gotten carrier aggregation doing that which makes it slower than the B353 router. Then again, it doesn't seem to want to come back switching to Auto again either. Hopefully that's something to do with them working on the local mast.
So this could be a bit of a fail as:
1) I wanted it so if 5G ever got enabled on the local mast I wouldn't need to check, it would "just work".
2) Its doing half the speed it did before the other mast got 5G, it used to be FASTER than the B353. (almost certainly the carrier aggregation issue though and I know it works on this unit as I had it on Voxi before)
I also have statistics from when I got it back on the local mast: