They have had their problems, just like every other provider around their size. Due to human nature, we usually only hear about the problems, and rarely, do we hear the good things that a company does.
We have been with them on and off, over 5 years. Any issues that we did have, were usually taken care of professionally and within a reasonable amount of time.
I would not hesitate to recommend them as a hosting provider.
EVERY server provider will have hardware issues, whether they are selling $100 servers or $2000 servers. The amusing part is that sometimes you get a $2000 server, and it has the same internal hardware as the $100 servers :-) You really never know what you are getting, unless you co-locate your own equipment.
All that matters is how they deal with hardware failure when it occurs, not if it occurs.
Actually, you can know what's in your server... well, I was using canaca for some websites of mine, and, when I first started to use them, they were like, we offer 20GB of space, and that was definately true ( I made some php scripts to make myself sure ), but later, they upgraded all servers to 30GB, or atleast pretended to, but truly, they didn't really upgrade anything... So, the point is, that you can know, if you know how to do it, what really is in your server...