I can't speak for their Cloud offering, but I have been using their Kimsufi Large (2.6GHZ) dedicated servers for around a year.
It's renewal time next week and my plan is to stick with them and drop my Slicehost.
Pros:
- Pricing is great. Hardware performs well. The value for money is far better than anything I can get in my own country.
- Most countries now have local sales/support teams so you can deal with a friendly local representative and they will deal with France and Octave.
- They're very fast with getting new Linux distros prepped for their manager system.
Downsides:
- Routes from your ISP to OVH may not be optimal. I've seen reports from people here complaining of routes going right around Europe the long way, from various ISPs.
- Pulling a large file from Novell to my Slice in the US I was getting around 2MB/sec but to OVH it was just a few hundred K/sec. Decide the value of bandwidth and where your customers are.
- I've had an unexplained reboot that I haven't been able to track down. It didn't bother me enough to track it down with support.
- The Manager user interface seemed to be a machine translation from French into English. Quite often the statements made no sense at all. This has improved quite a lot within the last 12 months though.
I've had more positives with them than negatives. Their Kimsufi dedicated offering suits me well and I'm incredibly impressed at how Octave has grown the company