I just got a set of DS93s for my 450, though it will be a few days before I maiden them. I spoke with Thomas at MKS USA, and - as I understand it they are basically DS95s with a less expensive motor. I took the plunge after two of my DS92A+ swash servo motors burned out from a crash. DS93s look like the way to go vs. DS92A+, and likely vs. DS95 if you care about cost at all.
I'll check back after I've smacked them around a bit, but I'm sure they'll be great - they're seriously fast, powerful servos.
Cheers,
John