The B-29 flames a bit easier than the B-24 I think. Feels like it to me, both being in them and intercepting them. Take a formation of them over a Capital, and you are VERY likely to lose 2 of them to the flak, especially if you make more than one pass. Last time I took a set of 29's over a Capital, I lost 2 in my first pass to flak. Both of them caught fire. Another thing to note, their engines catch fire very easy. This is from intercepting them that I know this, though I DID intercept in a 163. But it seems that it really doesn't take much to set their engines on fire. Some here have been lucky enough to find 29's while in something that doesn't have 30mm's, so they will have better information.
Another thing to note is that the bombsite on it is inaccurate. Drops are off no matter altitude, though it does get a little better the lower you are, it's still off. In any other bomber I can get to 30k, I can get laser precision when compared to the 29's bombsite. This doesn't really bug me as I only use the 29 for hitting a Capital, or once in a blue moon, towns. In a way, it's a good thing. I think HiTech intended it for use against the Capital and towns.