My friend...this is not easy to decide.
If you only use the cart on an original 7800
Take the GD
If you use multiple systems, take the Backbit
If you use the 2600+, take the Dragpnfly
A cheap solution is Matteos cart
If you wanna use 2600 games, maybe Concerto is ok
sure, some carts are not available anymore.
And my old CC2 is still in use today with its first
Batteryπ