Comparison between dbxml,tamino and eXist..

[Shuch]

Hi all,
i have a few questions:
1) i would like to know if someone knows the difference between
dbxml,tamino and eXist???even if its just the main comparisons....
2) how can i find the benchmark for these three native xml
databases??please try to give an explanatory answer as i have no idea
wat are benchmarks and how to find them?
3) disadvantages of dbxml.....advantages of eXist...
if anyone knows any of the answer out of these three problems...please
try to reply atleast for one of them...
any help will be greatly appreciated,
regards.