Some very helpful info, guys. Thanks.
I was almost going to go for the hydraulic (and probably will) although jnef's 6AWG comment worries me. I doubt I'll be going as large as 6AWG. 8 or 10 would seem to be enough for a FXS quick charger. The die sizes are listed as 4 - 70mm2 but I know how inaccurate eBay listings in particular are.
I've seen doctorbass successfully use the second one in a YouTube video, but the crimp got a little squashed and needed a trim afterwards to fit the connector.
My bike is still at least a week away, so I'm in no hurry.