If the path costs are the same then yes it loadbalances on per packet basis.
If the costs aren't equal then it chooses the path with the lowest cost.
did not notice that you asked about 2 destination.
The above is true for the same destination
Two routes to the SAME destination via DIFFERENT next-hops (which is what I think you meant by different destination )but the SAME METRIC, will load balance. If your interface is route-caching your load balancing will be per-destination, if you are process switching (eeek!) it will be per-packet.
The routes must be an exact match i.e same route and same mask length.