I have had a box with them on and off (more on than off) for the last couple of years. I'm not doing anything critical there, but have also had no issues. Everything seems rock solid (which it should be -- Wikipedia says that "The company has six datacentres housing more than 100,000 machines.") You can reinstall from the web control panel, they rent KVMs, not sure what else to add.
The major things people tend to bring up in forum postings are:
Kimsufi is the "non-professional" brand, and hardware support is slower than the OVH parent. Nothing ridiculous, but you aren't going to get a bad drive replaced within a couple of hours either.
OVH has "low quality bandwidth". Of course, people making this complaint never quantify exactly what they mean by this. I just tested on my "24G" box, and see 30-40MB/s to cachefly, 90MB/s to Leaseweb in Amsterdam, 75MB/s to Linode in London, 3-4MB/s to Linode in Newark and Atlanta, 12MB/s to SoftLayer in Dallas, 10MB/s to SingleHop in Chicago, 11MB/s to Joe's Data Centre. (Of course these are large test files.)
If you're interested, there's no setup fee and no minimum contract length (check this for yourself, obviously), so I'd say go for it.
5Tb as a limit really shouldn't be a problem for what I would use it for.
Then again for what I currently do 10Mbit would not be much of an issue either to be honest, though I'll ask about the procedure to reset this if I do set a sudden bandwidth spike one month.
There is VAT on top of that listed price, but even with that it is still a good deal if the kit and company are up to scratch. Last time I looked there was an extra cost for paying monthly, but that seems to have been removed.
> You can reinstall from the web control panel
That sounds interesting for a dedicated box. Are they using some for of SAN rather than each machine having its own local drives (so they can "reimage" your machine just by dropping its volume on the SAN array and creating a fresh one from template)? Or is this less instant (more like: make the request via the control panel and in X hours a passing support tech will plug a USB stick in and reboot to reinstall)?
You can customise the partition layout, but otherwise get a standard set of packages for whichever distribution. There's a choice of the usual Linux suspects in 32- and 64-bit, FreeBSD, Open Solaris and Windows Server 2008.
The process is fully automatic and a CentOS install takes about 20 minutes.