Does anyone have any experience of implementing a dataguard enviornment with 2 (seperate) databases on two nodes;

i.e. Server 1 has primary A and standby B, Server 2 has standby A and primary B.

This is obviously a cheap(er) solution (in that it waves on additional servers) that requires decent network bandwidth and server hardware, but is there anything stopping me from implementing this solution? And what are the things to look out for?