Matching UI to designs was horrible on Android, at least as of ~1.5yrs ago. Even if designers were shooting for "Material". Plenty of rough edges. I wouldn't say 2x-3x longer for a typical project, though.
I could see there being issues with relatively new-to-Android developers not appreciating the degree to which advice from the official docs, especially relating to structuring applications, should be taken with a largish dose of salt, leading to slow-and-getting-slower development as an Android project went along.