Round robin is now an acceptable psp for storwize. However if you don't want to change the psp for every lun you create, it might be handy to adjust the default satp for svc so that it uses RR for every (new) lun it detects.
First of all, lets see all the possible path selection protocols we can use (PSP)
~ # esxcli storage nmp psp list
Name           Description                      
-------------  ---------------------------------
VMW_PSP_MRU    Most Recently Used Path Selection
VMW_PSP_RR     Round Robin Path Selection       
VMW_PSP_FIXED  Fixed Path Selection    
We can see the default MRU for storwize/svc, which we are going to change to RR
First of all we can see that ESX will use a certain SATP if it detects an SVC / Storwize
~ # esxcli storage nmp satp rule list              
Name                 Device  Vendor   Model             Driver  Transport  Options                     Rule Group  Claim Options                        Default PSP  PSP Options  Description                                                               
-------------------  ------  -------  ----------------  ------  ---------  --------------------------  ----------  -----------------------------------  -----------  -----------  --------------------------------------------------------------------------
VMW_SATP_SVC                 IBM      2145                                                             system          
Conveniently this is VMW_SATP_SVC . We can now check which default PSP is associated with this SATP by executing the list rule
~ # esxcli storage nmp satp list
Name                 Default PSP       Description                               
-------------------  ----------------  ------------------------------------------
VMW_SATP_SVC         VMW_PSP_MRU       Supports IBM SVC           
You can see that by default MRU is chosen. We can change with the following command
esxcli storage nmp satp set --default-psp yourpsp  --satp yoursatp 
So execute
~ # esxcli storage nmp satp set --default-psp VMW_PSP_RR --satp VMW_SATP_SVC
Default PSP for VMW_SATP_SVC is now VMW_PSP_RR
Now reboot your server, the paths should be reclaimed with RR
