Wow this post was like reading a post from myself in the not so distant future. We had the
exact same experience on SoftLayer CloudLayer. Random I/O failures, read-only mode and of course the most frustrating part was the support process around that.
We had a week last month where we would lose a couple boxes a day to this issue at which point we said enough was enough and switched completely over to dedicated boxes (still from SoftLayer). Everything has been smooth sailing since.
To their credit SoftLayer (and probably more specifically our awesome account rep) stepped up and refunded us our money we spent on the CloudLayer in March (after some cajoling on my part) but their general reaction is one of a company that's completely disjointed. When I got really pissed and started bitching on twitter in March I received inbound contacts from multiple people on their sales/marketing/account mgmt team. Unfortunately these people didn't seem to be well connected to each other and are even less connected from IT (so they could empathize but not really affect change) and "management" (this faceless part of the company which seems to love to cut off it's own nose to spite it's face).
The oddest (and probably most infuriating) part of the whole thing is how everyone at SoftLayer went to great lengths not to acknowledge that the CloudLayer product had issues. They always seemed shocked by my assertion that something was very wrong with CloudLayer product and asserted that I was alone in seeing these issues. To this day I've still not read a single "we know something's wrong and we're fixing it" post from them and that's the part that bothers me the most because it implies that their either incompetent or disingenious. Neither of which are a trait you want in an infrastructure provider.