Alarm System: Gen 2 Base Station vs Gen 1 Base Station

Hi, I have a Gen 1 Alarm System and I just got a Gen 2 Alarm System. Comparing the Gen 1 and Gen 2 Base stations, they both look identical, and the Sku #'s are same. Anyone can shed the light, if the base station for Gen 1 and Gen 2 systems are the same in the station's features or how it works with devices, or the hardware/firmwares are different on the inside? I won't need to replace the existing Gen 1 base station - with the newly purchased Gen 2 base station? Or I should 'upgrade' and use the Gen 2 base station? Thanks.