I own a 5150 signature combo, and a Dual Recto 3 channel. It's hard to pick one man. It really is. OVERALL, when it comes down to the most general of generalizations....the 5150 is more clear or in other words, it's harder to sound muddy with a 5150 than a Recto. I'm going to get flamed for saying that, I know. But when these are the amps that I work with every single day in the studio, and nothing but metal bands come in...the Recto tends to be muddy compared to the 5150. The 5150 is a LEAD PLAYER'S AMP, generally speaking, so it's got more clarity, IMO. I often like layering the two though, because you can get things from one amp that you can't get from the other. The Recto has that Recto sound, which is great. But it's muddy most of the time. So you add the 5150 layered on top of it, and you get the clarity, PLUS the 5150 sound that is great as well. If I absolutely, no if's and's or but's about it, just HAD to pick one, it would be the 5150. But I bought both of them so I wouldn't HAVE to decide, hehe
. The JSX is next on the list for the new studio amp. The last one I bought for the studio was an Engl PowerBall, and it's like the metal god there. Just has such a great metal sound. Which has already been established. But the JSX...it's creamy. I love it. I keep going to the store and playing it. I might end up using it for myself. Anyway, it's hard to say. I would narrow it down to JSX and 5150 though. Good luck.
~006