OK, here is my reasoning for always taking gondolas.
The #1 "performance" criteria that I look for in any airplane is weapon load out. Number of cannon, cannon power/ballistics and ammo count is most likely to make me choose one plane over another. When I fly 109s, I usually fly the F-4 or the G-2. The Mgs in both of these rides is pretty piddly, might get you an assist, but for kills, cannon is where it's at. Taking the gondolas means that I have almost 3 times the ROF and killing potential.
If we were given the option of taking as many pairs of gondolas as we want, I would probably take 3 pair quite often, flying performance be damned! Imagine a 7 gun, 900 C-round 109F!
I guess it matches my flying and shooting style. I never limit myself to only clean dead six D-200 shots, I take anything I can get; high deflection merge, HO, dead six, turning circle snap shot, high six bounce, shots at any range, vulch or what ever. I need ROF for how I fly and shoot. As a result, when I do kill someone, it is very often right away on my first attack. Most of my fights are very short, (when I win).
I don't think the gondolas hamper the flight performance that much. Top speed and max stall turn suffer mostly, but not that much. With gondolas, you can still outrun Zekes and Spits. Without them, you can't out-turn these planes for too long anyway. Most planes that are faster than the early 109s can't turn with gondola equipped 109s either, so it's no great loss. I think fuel state has a bigger impact on flight performance than do gondolas.
About the only time I get mad while playing AH is when I get ½ way to an enemy base and notice that my gondolas are missing (You know the drop-tank/gondola bug that de-selects gondolas without telling you, when drop tanks are disabled at a field that you took off from).
Still, I am often surprised as to how well I do without them, when I enter a fight discouraged because I think I won't survive without my regular fire-power.
eskimo