These router redundancy protocols operate in a multi-vendor environment and most vendors support them, but you won't know if they play well together until you test them. Implementing the standards-based approach gives you more product choices and, even if you use only one vendor, standards give you the freedom to switch to another vendor someday. We don't recommend you use equipment from more than two switch and router vendors as this could add too much overhead in vendor management. But you may want one vendor's gear at the core and another's further out.
Test everything thoroughly before deploying router redundancy protocols, whether you run a multivendor or single-vendor environment. Redundancy increases uptime but adds complexity, which can work against uptime. Make sure you exercise all failure mechanisms and observe how they work, so you know what to expect and what your management software can tell you about the status of the components.
In the end, it's all a matter of how much downtime your applications can handle and how it will impact the the business. In some cases, you may be able to handle a network outage of a few hours while you replace a switch with a spare; in other cases, a few seconds could spell disaster.