With Andre's help, we migrated Mephisto from Rimuhosting to a Lifetime (sorry guys, deal is over) Joyent Accelerator. $649 compared to $40 / month. No need to even think twice about it.
Two initial impressions. Solaris is going to take some getting used to, and not NEARLY as slick as apt-get, but I'll deal. Next, this thing is freaking fast. I don't know how it compares to slicehost in terms of speed, but page refreshes are near instantaneous for writes to the DB, which wasn't the case on Rimu.
I'm a happy camper, and over the long haul, I'm saving a ton of money.