["I will be upgrading to Telus Fibre Optic 150/150 when it becomes available this fall in my area. Then I guess I'll really be able to see whether it's my current service or if it's just Clipstream's deficiency."]
Bandwidth isn't really the problem any more (except when it goes below 5MB/s or so, I guess), it's CPU and memory, and what you are running besides it.