I picked the Stiletto, mainly because that is what I am using right now. I know that is a bit of a cop out, but that is the short answer.
The longer answer is I play a Stiletto because it is the best amp for me in the context of the band I play in. I loved my Roadster, but I felt that it just wasn't holding up next to a Triple. The fundamental sound was too similar, so the extra headroom just made the Triple far more forward in the mix. The Stiletto allows me to carve out my own part of the frequency spectrum, and fits in well with Triple. It is amazing how playing together gives us one huge, complex sound, yet when we play harmonies, you can really hear that it is two guitars; before, it sounded closer to one guitar through an Eventide. It also doesn't hurt that the Stiletto is giving me the best lead sound I think I have ever had.
If I was in a single guitar metal band, I would have kept the Roadster. It is stupidly versatile, and I absolutely love that massive low-mid Recto rhythm attack. Mike flirted with buying a Stiletto for a while, so I like to joke that I like the Roadster less than Mike likes his Triple.