The RS1 has lower capacity than the RS2, in terms of the number of radio channels it supports. The RS1 was deployed to a limited extent by T-Mobile UK and in tiny amounts by O2 UK. It is no longer being supplied in the UK.
The RS2 has 3x the radio capacity of the RS1 and is deployed in the UK with a configuration that allows the mobile operator whose network it is configured for to turn it off by setting particular parameters in the network.
In all other respects the RS1 and RS2 are the same, they are locked to a particular network, only boost that network’s radio frequencies and implement hardware and software algorithms that completely protect the network from the harmful effects usually associated with repeater products.