I believe that with Bell you get a 1 year warranty on equipment? (correct if wrong).
With Shaw you get a standard 3 year warranty, if you subscribe as a triple play customer for all 3 services you get a lifetime warranty on all purchased equipment. On some specific equipment you can part exchange and upgrade to a higher level, eg HD Terminal for HDPVR to receive a discount off the higher piece you may be after. If you own equipment and move out of the Shaw service area Shaw will buy it back at a reduced rate regardless how long you have owned it.
If you have an issue with your equipment and someone needs to come out to check it out it would typically be a free call and it found defunct would be replaced by same, similar or better piece of equipment.