Yeah, 5150 works better for tight thrash type metal. I love Mesa 2x12 cabs.
With that said, the Triple Recto is more flexible (assuming it's 3-channel) and is downright mean.
Pros for Recto
-better resale value
-more tone capabilities
-it's a Mesa
-better cleans
-bigfoot makes switching channels a breeze.
-heavy low-end
Cons for Recto
-more expensive to replace tubes - sextet instead of quads
-active eq, more care needs to be given to find the sweet spot
-Mesa cost more
Pros for 5150
-easy to eq
-cheaper
-dependable (but so is the Recto)
-simple amp
-nice crunch
-you would get the Mesa cab
Cons
-not as flexible
-cleans are sterile
For me, the Triple Recto would be the first choice due to the flexibility. However, if you don't need the flexibility and are looking for something with a more practical price tag, then the 5150 is a great choice.
They are both great amps.