Just received my order of the XT-60 and I cannot see anything wrong that jumps out at me. They slide in and out nicely and the 'connector' part is not loose but firm in the base.
Only now to see if they pass the soldering test but I know how to solder so I doubt I'll melt them.
I have a few tanks coming down the assembly line so to not waste them (I ordered only 2 pair and they sent me all these) I'll try 'em out!

(But not in my Panther)
~ Jeff