Hi,
All products mentioned have advantages and disadvantages (complexity, scalability, etc..) It really depends on your requirements. NetWorker has the best cross platform support I've seen, where as from my experience, tech support with Veritas is better than Legato's.. Veritas is more expensive, but is it with it to get their support? Some say yes, some say no.
I think the bottom line is this.. Before making any decision, evaluate your short and long term needs, figure out how much money you can spend, do some testing and make your decision based on that.
Good Luck!
-ag100