As has already been suggested its down to personal preference really, but if in doubt the nero's do perform well imho.
The most important thing is to make sure that the tread depths front to back do not have a difference of more than 2mm (Subaru recommendation), otherwise this will change the rolling circumference and wind up the differential and possibly make it go pop as below........
http://www.iwsti.com/forums/warranty-se ... -help.html
Its always better to rotate your tyres front to back on a regular basis, such as every service.