Both topologies work in a similar way, as the only voltage gain is provided from the transformer itself. The transistors only handle the current gain. The one on the left references the signal to ground and usually offers increased stability, for the lack of Miller capacitance effect. It might also have a broader frequency response, especially at higher frequencies. In simulation (with some modifications), I got it to work reliably up to 200+MHz. This is also because of the lack of Miller Capacitance.
