It's good to charge with Sony charger, because it charges xperia p quickly till 80%. And ofcourse guaranteed to provide voltage/current according to specifications
But, samsung chargers are also of good quality, so if you don't find your Sony charger once in a while its okay to stuck it into samsung charger. But I would say be careful with other local chargers which may not be complying to voltage and current rating, which may damage your phone
