Personally, I dislike the belly patch on the new 109E. This is because it's at a different scale from the rest of the fuselage pieces. 1 pixel on the belly patch turns out to be about 1.5-2 times as wide as 1 pixel on the fuselage sides. This makes its panel lines always look misaligned and too wide. It would have been better, IMHO, to have done without it if it could not have been made to the same scale as the rest of the fuselage. On the belly, which is always 1 color, it's no biggie that the sides get stretched down there. If we have to have separate pieces, I'd rather have one for the top, to make camo color divisions flow over the top better. Of course, it would have to be at the same scale as the fuselage sides.
I have several other minor nits to pick with the new 109s in general. However, I must say they're all MUCH better than the originals. It's just a shame that in the E and F can't carry bombs, despite having bomb racks on the skins and these showing up in the skin viewer (not to mention the F's partial gondolas).