The 4-watt Alessandro Runt. This is the only 10" speaker I've spent any time with so I can't comment other than to say it doesn't have the warmth or mids of a 12" but no surprise there. For recording, I expect to use it to inject a little grit along with the 12". There are videos of Derek Trucks using a Runt.
I like the fact that it is only 20 watts, could make for a more dynamic response than say the Copperhead which is 75 watts. I like the Copperhead in my Princeton Reverb but I have always wondered what the original CTS and Jensen C10N sounded like.
I asked Eminence's Technical Support for a comparison between the Copperhead and the GA10-SC64 and this is what he replied.
The GA10-SC64 has a lot of similarities to the Copperhead, but warmer and smoother in the upper-mids and highs and fatter and more full and defined in the lower-mids and lows.