i wanna say final ichigo, just based off of feats. but we have yet to see true ichigo do anyting more than make star knights look silly. as to why star knights are able to sense his reiatsu, it could be one of 2 things: he could be suppressing his reiatsu just like aizen did when he transcended, or it's because he is only in shikai unlike final ichigo who was in bankai. strictly speaking though, true ichigo should be as strong at least as final based off what we know. this is suppose to be his true powers, his true potential thus either final ichigo was that also or it to was just a fraction of his power. just based off that knowledge, true should be stronger. but until we get more info, we have to put final ahead of it.