Enable 3g on both sims?

However, in this thread: Widget to switch on / switch off SIMcard 2?
the posters apparently use the 2nd SIM slot for 3G traffic (including data). So maybe the specs are misleading?

Indeed, that’s me, and I definitely confirm my FP (second gen.) gets 3G with my office “data-only” SIM in slot 2 (in slot 1 I have a “GSM-only” Simcard). Now maybe the case is different for the previous FP generation?
Also in my system settings everything 3G is compatible with SIM2 slot, among others there is a specific choice for “data associated to SIM2”, etc.
When in 3G the SIM2 level-meter can show the same E, G, H… minute indicators according to network availability.