Go for Grand if possible. Trust me, Galaxy Grand smoke away Galaxy Win miles away. Although Grand are using 1.2GHz A9 core + Video Core IV, are way better than Win Quad-Core 1.2 A5 core + Adreno 203.
Subway Surfers problem can be solved (If you having it) by upgrading your firmware. OTA or ODIN.
Samsung Galaxy Grand DUOS GT-I9082 | Stock XXAMF5 4.1.2 (2013-06-11) ROM (ROOTED) | CWM Touch Recovery 220.127.116.11
Samsung Galaxy Ace GT-S5830 | Stock DXKT7 2.3.6 (2012-10-13) ROM (ROOTED) ~Changes from time to time~
Toshiba Folio AS 100 | Cyanogenmod 10 A5 4.1.2 (2012-11-17) ROM by DerArtem | CWM Recovery 18.104.22.168
"I'm XDA newbie "