Here's what we have used:
It should be noted WITH REGARD TO WARRANTY the majority of manufacturers DO NOT SUPPORT OR WARRANT their products at all if they are purchased ONLINE from an unsupported company or the purchase is not verifiable.
ACTi: send back to office in california - we are resposible for shipping charges one way. Can take weeks to get items returned. Have been able to get advance replacement a few times with us paying the cost for shipping and the cost for the new items - not sure if we have received credit for items yet if so it would be recently and it took a couple months.
Arecont: use to be able to take to distributor but the last time we couldn't everything had to be handled through mfg. It can take weeks to get replacement or repair. We are responsible for shipping costs. We have not gone through this process in a while so it could have changed.
Avigilon: next business day advance replacement - Avigilon pays shipping both ways - advance replacement goes on credit terms and get's taken off after they receive the defective device - this generally takes a couple weeks to get credit back. Must go through RMA & troubleshooting process with tech support (takes about 5 minutes sometimes longer) then you sign via online service. There are no distributors to purchase from. It is all mfg direct.
Dahua (purchased from US source): camera must be sent back to company that we purchased it from. We pay shipping there they pay shipping back. Getting cameras fixed and returned takes weeks.
Warranty (and support) is something after the fact that bites a lot of people in the butt. It's great to save money up front but it stinks to be a position without reliable support & product warranty when you really need it.
This is good topic because the overall cost of a solution or product for both end users and integrators depends on ease of use, quality/durability/reliability, technical support quality & cost of doing business (purchasing, shipping, Warranty/RMA, etc) over the lifecycle of the solution/product.
It can also change by type of device. Maybe this can go in the camera finder tool.