Having had all three services (Bell, then Shaw, now MTS)... I will give you this quick guide.
SD Quality (out of 10):
- Bell: 7
- Shaw: 6
- MTS: 8
HD Quality (out of 10):
- Bell: 8
- Shaw: 6
- MTS: 7
PVR (out of 10):
- Bell: 8
- Shaw: 7
- MTS: 8
Reliability (out of 10):
- Bell: 5
- Shaw: 7
- MTS: 9
Price (out of 10):
- Bell: 6
- Shaw: 7
- MTS: 9
So I give it to MTS, with Bell being a very close second, and Shaw lagging behind. I used to have screenshots showing just how horrible the macroblocking was on Shaw during sporting events and any action scene in any show on any channel. I'll try and dig them up.