I use scalr at the moment(paid service) we have just under 20 instances spread among 6 farms. Been using them for about 3 months now with very few problems. The only major issue I've had is that their DB roles aren't great for large db's(>100gig) though I think they are working on an SBS one.
As it is I use a modified role to allow SBS but have to muck around too much for comfort on start ups since the SBS partitions don't always mount at startup(sometimes up to 10 minutes later) and when they do that the DB init scripts fail which causes scalr to cycle the instance and start the whole process over again. That said I've only had to do that twice since I've used them.
As it is I use a modified role to allow SBS but have to muck around too much for comfort on start ups since the SBS partitions don't always mount at startup(sometimes up to 10 minutes later) and when they do that the DB init scripts fail which causes scalr to cycle the instance and start the whole process over again. That said I've only had to do that twice since I've used them.