It is still a good phone for the price range, screen is very nice being super AMOLED. You may want to also consider the Moto G lineup
http://www.gsmarena.com/compare.php3?idPhone1=5213&idPhone2=5831
Both having 1 GB RAM, you will see a difference between 2 cores and 4 cores when running certain apps. There's the Moto G 4.6", Moto G Plus which adds 4G connectivity and Micro SD card slot, and Moto G 2014 which further adds a 5" screen. You can use the above link to compare your phone against others.
Moto G lineup has a "vanilla" android looks, with no extra apps, very light to load, and they plan to upgrade to Android 5 "Lollipop", wheras the s2 plus just got jellybean 4.3
Spec wise it would look you could get more from the Moto G... but in the end it also depends a lot in what you want... if you really like the s2 looks and its interface, then you buy that one.
Good luck.