Faster, so very less delay in CS call establishment.
Source base station deletes the UE context immediately after sending the RrcConnRelease (Redirected info).
Handover to other RAT:
Adds extra delay in establishing the CS call as source prepared the target before giving the HO command.
Advantage with HO is we can handover the PS services also.
In HO source base station delays the release of UE context, so that if HO fail UE can return using the reestablishment.