I'm currently with Magma and haven't had any problems with them (they've always been professional, courteous, prompt, and didn't act surprised or annoyed upon learning that I run Linux), so no pressing reason to switch,
I remember being on a phone call to their tech support, for work purposes, solving a problem. The fellow on the phone seems quite comfortable with the tools I was using, so I asked and got the reply: "Oh yes, I use linux both here and at home." Ah, no wonder such decent resolution!
Magma's "myaccount" ticket system works fairly well too, much better than the bit-bucket now at igs. It would appear that recently magma techs are being knocked on the "time-to-close" metric, so they close stuff sometimes without checking. Annoying, but I've never had to re-open twice.
Anyway, from a professional stand-point, I'm comfortable recommending magma.ca. Gord.