Would a g2 with gondolas handle as well a g6 without them? point is a g2s gun package is weak enough to necessitate needed them a g6 has a much more effective gun package so gondolas arent really needed.
Compared to the Es (especially) and Fs, the G2's gun package w/o gondolas is quite adequate. IMO, all 109s have enough ammo w/o gondolas if you get experienced enough with them to know you have an asinine amount of cowl gun ammo compared to your limited and precious few cannon rounds (which I save for real good shots at short bursts). If you shoot like that, then a G2 w/ gondolas is penalized by flying with them equipped, but I think you will find it's lethality with that package is more than adequate (again, shooting cannon ammo very conservatively).
If you're comforitable shooting w/o gondolas then you might as well fly one of the later models that do very well w/o them on. But I still feel the the G6 and beyond was the beginning of the 109's being very picky about what speed you were doing maneuvers at (with or without gondolas). They handle well, but if your going too fast or too slow when doing a particular maneuver it can be a fatal move in a dogfight.
G-2 has better front view than the later ones, which have the MG bulges blocking far too much of the front view. G-2 is nimble, but I would not take gondolas on it, unless you fly with friends or are a crack shooter. With gondolas you will find it hard to get entangled in a furball or when you want to disengage.
If you want to go after buffs, you will want the gondolas. Then take G-14. It has the power to carry them. You just need to avoid the hardest turn fights and fly more conservatively.
Above comments in Late War Arena context.
I've had a blast in a G2 in the LWA w/ gondolas in furballs, flying in the same conservative way you suggest flying the G14, you just need to remember you have the extra drag and fly to conserve your energy.
But, I still don't like taking gondolas for buff hunting with the G14. I prefer the 30mm for G14 buff hunting (with maybe a DT, but no gondolas), and I prefer a G14 with the large 20mm package for dogfights (a lot more firing time than a 30mm, plus if you use it conservatively for good shots, the 20mm is adequate for taking off wings in a couple shots. no DT or gondolas). Kinda related, but kinda off topic, I really wish the K-4 had a high-ammo 20mm cannon package sometimes for the same reasons above, I really really do.
Well this morning I took the G6 out for a spin and really liked the way it handled. But, the guns suck IMO. I took the 20mm gun package, 50% and DT. Converengence set at 400 and dove in on a set of lancs, started firing at 600 from high 6, and it took me 2 passes for each bomber to bring them down. The same approach in a 51 and I can down them on 1st pass almost everytime.(convergence @300)
But on the upside, I found the G6 to man handle a spit16, although spit pilot was somewhat noobish. I didn't kill him but he ran away with a bloody nose 
I think tomorrow i'll try the G14 out. 
If I'm going buff hunting specifically and want a later cannon heavy German fighter, then I take up a Ta-152H (technically a 190 variant, but it rules for buff hunting).
I've found that DTs on 109s are never a good thing unless you're buff hunting or really need the extra fuel (100% fuel is the way to go most of the time, in rare cases where I'm scrambling from an airfield into a nearby furball at 2-5K, then I take one with 50-75% fuel). I've also found that 9/10 times when I'm considering taking gondolas on my 109 for X reason, I'm considering the wrong plane type for that sortie. I go back to the beginning of the thought process and consider if the 109x with gondolas is really the right plane for the sortie I'm considering.
Regarding convergence, the 109s are the only plane in AH I think I set the cannon at a drastically different convergence than the cowl gun's convergence in each plane. On the G2 and earlier, my cowls are around 175-125, and my 20mm cannon to 225-200. On the later models, my cowls are around 200 give or take and my cannons around 300-250.
The cowls are already mounted pretty close together on the nose and have great ballistics, and especially with the earlier smaller caliber cowl guns, they really only do damage at closer ranges and in a nice tight grouping. If you're shooting your cowls into a wing for more than 3 solid seconds at 200-400 yards, then start messing with your convergences, because I can vouch that the cowl guns are lethal when properly converged and used at the proper ranges in bursts.
The cannons are a totally different bird for the 109s than the cowls, other than they are placed close to the cowls on the nose. 109s feature either the 20mm MG/FF (with only 60 rounds and horrible ballistics and rate of fire
), the 20mm Mg151 (plenty of ammo with 150 or 200 rounds, best ballistics of any German 109 cannons IMO and the fastest rate of fire
), or the much feared 30mm Mk108 (only 65 rounds and a slow rate of fire, and ballisticaly it's better than a 20mm MG/FF IMO, but still pretty bad). Each handles differently, and really the best practice/feel you can get for the first time is to go in offline mode and unload them each a couple times into some drones without any cowl guns.
If I'm confusing more than helping, please let me know, I have a habit of writing walls of text when I don't intend to.
