Other benefits of Gold for your situation though will be:
1. First check-in (can be really useful in some situations e.g. summer holiday weekends at LGW)
2. Fast track security at non-UK airports is more widely available as a OneWorld Emerald than a Sapphire...(CPH, HAM, several others in Europe where you can get fast-track as a BA Gold but not as a Silver)
3. The new "First Wing" coming to LHR T5 from April could be a nice way to cut down on security lines...
4. Extra availability on economy reward seats for the three of you
5. Ability to force a "double Avios" award seat out of cash fare inventory in an emergency...can be really useful for last minute short-hauls when cash fares are high
6. Ability to pre-select more seats, and also to "link" other bookings to yours for advance seat selection (useful if travelling with friends on different bookings)
7. Gold line are kinda useful
8. Some "soft" recognition is possible on board - not always, but last few flights in WT/WTP I got a sneaky glass of champagne etc.
Erm - probably some others I have forgotten. Many of the above can be useful to you even when travelling as a group of 3.