Thanks for all the advice, guys.
OK, this is the story so far. I tried the 109G10 with only the 20mm cannon (150 rounds at start). It doesn't last long, although the plane probably flew better than with the gondolas. But I do feel that in this configuration, the guns lack the punch that you need in a game like ours.
So then I changed the config to the 30mm hub cannon, and flew for a couple of hours. Sure, one ping is all you need to down most fighters - a P47 needed more than one, and buffs need several. Again, the ammo does not last long. BUT!!! - it's so hard to get those 30mm rounds on target. You have to get in
very close, and what I found was that the bogie pilot HEARD my plane (at 100 yards) before he saw it!

Instantly, the bogie would break off... Also with the 30mm, one can forget about deflection shots. If you disagree, perhaps you could submit film to substantiate your point of view?
So I'm back with the gondolas. With this config, I can begin shooting at 400 yards, not 200 or 100 as with the 30mm.
I find that downing a buff with the gondolas on is as effective as the 30mm hub cannon config. because I can fire for longer without depleting my ammo.
The G10 does not fly as well with the gondolas, but in view of the other considerations, I think the gondola config. is the one I like best.