G6 is an outstanding aircraft and a truely amazing one once you learn it. She doesn't have the engine power or the top end speed as some of the other 109s ( not including the E, F models ).
Her firepower is her biggest assist since it has the 13mm cowling MG guns instead of the 7.9mm cowl guns on the G2. Her maneuverability is also debatable. On paper, yea her maneuverability is worst than that of the G2, actually the G2 is superior in every way to the G6 except firepower.
The G6 also has some of the best 109 skins in the game and that is another reason why i fly the G6. ( Best 109 JG11 skin to date ) & the extra firepower mixed with my excellent gunnery makes short work of bandits once i saddle. I also do not have no problem making the G6 dance like a G2, you just have to be aware of your surroundings since once she's slow it's a pain building E because of the engine power.
The 20mm combined with the 13mm MG cowlings makes short work of alot of single engined fighters. Shouldn't take no more than a 1-2 second burst to down a fighter if you're hitting some critical spots ( I normally aim for the wings or cockpit. )
Also another note, the G6 can't catch alot of the Late war planes in a drag race so chances are if you're being tailed and don't have the E or Alt advantage you'll be engaging him
very soon.
Hope this helps.