The 229 was going to be powered by a Jumo 004 engine (like the 262) which might not have been the best choice, whereas the E.583 and the P 215 were going to be powered by the superior Heinkel HeS 011 and the P.13a by a coal-powered ramjet IIRC, I know the Germans were still going to lose the war but would any other designs have been better than the 229?