they are very sweet, and worth every penny they cost...
i never really compared the 60L to a G12T-75..
I have 20 Hellatone 60Ls in an x-pattern with 2 G12T-75...i think its the ultimate speaker combo...each speaker works to compliment the other sonically, and gives it a thick rich tone..
The hellatone60 is similar to the speakers from the marshall mode4 mf280 cab...its a vintage 30 with emphasis on keeping the lows nice and tight, and the highs not too ice-picky...
The hellatone differes further by not having such a "harsh" upper mid spike...its smoothed out as well as the bass being tightened...i think they do very well when paired with the T-75..both have different characteristics for high/low frequencies..and where one is more "scooped" the other is a bit "heavier." The other guitar players bought v30s to xpattern after hearing my cab, and he hated it...they were new and not broken in, and werent hellatone....tried to explain to him there is a big difference between those and a straight up v30..
ever since i owned and sold my mode4 cab, i wanted to make sure my cab in my next metal band had these speakers...and all honestly they are better than the celestions in the mf280..